The number of workers who share data between a computer in the office and one at home grows with the popularity of home computers. Vendors have introduced different types of storage to meet the challenge of transferring more than a couple of megabytes of data between non-networked machines. Most of these solutions have garnered lukewarm acceptance because of cost and performance problems and the necessity for special hardware to read and write to the chosen storage media. A much better solution exists in the form of flash memory devices that use the USB interface. Connected Home has gathered some of the most popular USB flash storage devices to test their usability, performance, and special features. Most USB flash storage vendors offer devices in a range of capacities. We asked vendors to submit devices with the largest capacity and the most features. See Web Table 1 (http://www.winnetmag.com, InstantDoc ID 27420) for a comparison of product features and prices.

Installation
All the devices I tested have a similar form factor—about 3.5" long and 1" wide—with the exception of SanDisk's Cruzer, which is wider to accommodate replaceable media. Most of the devices are available in various capacities, and each model sports a unique color scheme identifying its capacity. All the devices feature some type of USB connector protection in the form of a cap or retractable connector mechanism.

Numerous operational abilities and requirements are common across the products. All require special drivers for Windows 98 and operate in Windows XP, Windows 2000, and Mac OS without requiring a vendor-supplied driver. All the devices feature an activity-indicator LED that lets you know whether the device is busy or whether you can safely remove the device from the system. Before you can remove a device in Win98, you must wait a few seconds for the device to go into standby mode, signaled by a slowly flashing LED. To remove a device in XP, you must use the Safely Remove Hardware utility, and in Win2K and Windows Me, you must use the Unplug or Eject Hardware icon utility in the system tray before physically disconnecting the device. In Mac OS X, you must eject the device before removing it.

Sony's Micro Vault USB Storage Media. The Micro Vault is available in 16MB, 32MB, 64MB, and 128MB models. I received the 128MB USM128 model in its retail blister pack. I followed the documentation's instructions about using the media for the first time. I placed the mini CD-ROM containing my Win98 device drivers into the CD-ROM drive on a Win98 system, inserted the USM128 into the USB port, and let the New Hardware Wizard search the CD-ROM for the driver. The driver installed easily, and the USM128 appeared in My Computer as a removable disk. I removed the USM128 from the Win98 computer and plugged it into a laptop running XP Home Edition and a Win2K Professional desktop system. Both systems recognized the device but inexplicably reported it as a Sony DiskOnKey device, and an OS-supplied driver was automatically installed to support the device.

M-Systems' DiskOnKey. The DiskOnKey is available in 8MB, 16MB, 32MB, 64MB, 128MB, 256MB, and 512MB capacities. The 512MB model I tested arrived in its retail packaging. KeySafe, M-Systems' security implementation, is preloaded on the DiskOnKey; but if you're using a Win98 system, you must download any necessary drivers to install the product before you can access the preloaded files. I downloaded the Win98 driver software, Windows NT driver software, and the latest version of the KeySafe security software from M-Systems' Web site. I ran the Win98 driver installation program on the Win98 system, then inserted the DiskOnKey, which the system automatically detected; the device then began loading the appropriate drivers. The XP, Win2K, and Mac OS X systems all detected and used the DiskOnKey with ease. DiskOnKey also supports NT, which I was skeptical about until I tested this capacity. I installed the NT driver on a system with NT Workstation 4.0 installed, specified which drive letter the storage should use, and performed a necessary reboot. The Removable Disk volume is present whether or not the DiskOnKey device is installed, and the volume behaves like a CD-ROM drive, prompting you to retry or cancel when media isn't inserted. Overall, the DiskOnKey operated well in all of the OSs, including NT.

Targus's Go-Anywhere USB Drive. The Go-Anywhere uses the same hardware that the DiskOnKey device uses, so the functionality was the same as that of the DiskOnKey I tested. The Go-Anywhere device is offered only in 32MB, 64MB, and 128MB capacities. The 128MB Go-Anywhere PA128 model that I tested came with a Targus-branded version of the DiskOnKey User's Guide and a CD-ROM containing Win98 drivers. I used the latest drivers and KeySafe software to test this product, which performed much like the DiskOnKey. To satisfy my curiosity, I tested M-Systems' NT driver with the Go-Anywhere. The driver worked, although switching back and forth between the Targus and M-Systems devices didn't proceed smoothly. Whether this problem is due to volume size or a difference between the Targus and M-Systems hardware is unclear.

Global Channel Solutions' EasyDisk. The EasyDisk removable USB electronic hard disk is available in 16MB, 32MB, 64MB, 128MB, 256MB, and 512MB capacities. All models support an identical feature set except the 512MB model, which doesn't include password or bootable functionality. I tested the 16MB ED1016 model. I installed the Win98 driver by double-clicking setup.exe on the installation CD-ROM, then installed the EasyDisk device in the Win98 system; the system detected and provided a drive letter for the device within seconds. I experienced a sporadic error that required system reboots. EasyDisk's documentation states that the device is compatible with Win98 Second Edition (Win98SE) but doesn't mention support for the first edition. My subsequent testing of the device on Win98SE was trouble-free. My XP and Win2K test systems recognized and supported the EasyDisk device quickly without prompting for driver installation.

Transcend's JetFlash USB Flash Drive. The JetFlash is available in 16MB, 32MB, 64MB, 128MB, 256MB, 512MB, and 1GB capacities. I received the 1GB model in its retail box. The online product documentation in Adobe Acrobat Reader format was the most thorough of any of the products. The JetFlash has a somewhat elliptical shape that can interfere with cables in close proximity to the USB ports on your system. A USB extension cable is included with the product to solve this problem. After I installed the Win98 driver from the CD-ROM, the device functioned flawlessly on XP, Win2K, Win98, and Mac OS.

SOYO's Cigar Pro. The Cigar Pro is available in 16MB, 32MB, 64MB, 128MB, 256MB, and 512MB capacities. A 1GB model is due in late 2002. All the Cigar Pro models share the same feature set except for the 16MB model, which offers basic storage with no password or security features. I received the 512MB model in its retail blister packaging. I double-clicked the Win98 driver installation executable, then inserted the Cigar Pro into the Win98 system, which immediately recognized the device. Both the XP and Win2K systems also recognized and immediately supported the device.

Cruzer. The Cruzer is a bit different from the other products I reviewed: The device is a USB interface that accommodates a Secure Digital (SD) memory card for storage, and thus is upgradable. Another advantage to the SD card is that it lets you use the Cruzer with more devices than the other products. The retail package for the 64MB Cruzer I tested also contained a 4" USB extension cable and a CD-ROM. You use the three-position slider on the Cruzer to extend the USB connector for typical operation and tuck it in for transportation and to eject the SD card. The extension cable will likely be required on most systems because of the Cruzer's width. Like the other products I tested, the Cruzer requires a Win98 driver, which I installed from the CD-ROM, and the device worked with the other supported OSs without my having to install a vendor-supplied driver.

Security Features
The Micro Vault storage devices ship with Security Zone software on the included CD-ROM. Security Zone works only on XP and Win2K systems. To install Security Zone on my XP system, I inserted the USM128 device into the computer's USB port according to the product's instructions, then double-clicked the installation program on the CD-ROM. All the installation program would do was issue a noninformative error message. After reading the instructions more closely, I copied the executable installation file to the desktop and the Micro Vault device, then double-clicked the icon on the desktop to successfully launch the Security Zone software. I was prompted to type a password and use a slide control to specify a capacity on the Micro Vault device for the Security Zone. The software reformatted the device with one Security Zone in the size I specified, and the device's remaining space was allocated to the Public Zone. The Security Zone software then copied to the Public Zone on the device. You can launch the Security Zone software on other systems from the Public Zone on the device. I removed the USM128 from the XP system and took it to the Win2K system and successfully accessed the Security Zone software from the device's Public Zone.

KeySafe security software comes preloaded on the DiskOnKey, but I downloaded the latest version for testing from the M-Systems Web site. The software installs similarly to Security Zone and has similar functionality. The main difference between KeySafe and Security Zone is that the icons in KeySafe are labeled more intuitively. The Go-Anywhere also includes the KeySafe security software.

The EasyDisk and JetFlash share the same security software and features. Both devices have a small write-protect switch that you can slide to keep from overwriting or deleting existing data. To password-protect the contents of either device, you use the Media Format utility to reformat the device with the Enable password feature. This feature protects the device's storage area. When you select Enable password, an executable file, passid.exe, is copied to the device. When you insert the device in your system, you must execute the passid program and enter a password before you can read from or write to the media. After you enter the correct password, a system tray icon appears that lets you lock and unlock access to the media.

Both XP and Win2K support the Cigar Pro's security software. I installed the software on my XP system from the CD-ROM, and an icon in the system tray let me resize the device's security and public zones partitions. After I selected the sizes, the partitions were resized in approximately 1 minute and the security installation executable was copied to the public zone. I inserted the Cigar Pro into the Win2K system and double-clicked the setup icon in the public zone to install the software. By right-clicking the security icon in the system tray, you can resize partitions, change the password, log on, log off, or exit the security software.

The Cruzer includes CruzerLock software, which encrypts and decrypts files stored on the Cruzer. I copied the CruzerLock executable to the Cruzer according to the online documentation, then opened the CruzerLock program. The interface was easy to use and the program did its job, but there were a few annoyances. You can select files from only one directory at a time for encryption or decryption; you can't encrypt an entire directory structure in one operation. Also, when files are encrypted, they go into the secure directory, which doesn't maintain the directory tree structure from the files' original location. If you need to encrypt only a few individual files, this solution is workable, but more intelligent file handling would improve the product.

Interoperability
I tested all the devices on XP Home, Win2K, Win98, and Mac OS X for interoperability. I also tested the devices claiming support for Linux on Red Hat Linux 7.3. Cross-platform tests between the Windows and Mac OS platforms were uneventful: All devices operated as the vendors claimed. Among the devices that claim Linux support, none furnish documentation for configuring that support. I found unofficial documentation for Linux support on the Web and was able to verify that the devices that claim to work under Linux do mount as a Virtual FAT (VFAT) volume. I was able to read from but not write to the USB storage mounted as VFAT. The different security implementations that the devices offer support varying platforms; however, all the devices support the interoperability of a secured device between XP and Win2K.

Effective and Valuable Tools
All the devices I tested effectively move data between USB-equipped systems. Aside from selecting the capacity you need, deciding what type of security model fits your needs might determine the best product for you. If you like the idea of split secure and public zones, the products from M-Systems, Sony, SOYO, and Targus will deliver; the EasyDisk and Transcend products secure the entire storage area. The Cruzer is the only product in this group that encrypts files, but the software for doing so is a bit clumsy. Although performance was acceptable across the board, some products performed better on certain platforms. The Cruzer cruised on Win98 but demonstrated below-average transfer speeds on a Macintosh. The EasyDisk lagged behind the other products in Mac performance, and the DiskOnKey maintained the most even performance numbers across all the tested platforms. (See Web Graph 1 for a comparison of how much time a 12.5MB data package took to copy to each device from each of five OSs.) The Cruzer and DiskOnKey get bonus marks for compatibility: The Cruzer uses standard removable SD memory cards, which can be shared with devices such as Pocket PCs, and DiskOnKey supports NT.