Online retailing giant Amazon on Tuesday launched its cloud-hosted file storage service, Cloud Drive, well ahead of anticipated competition from Apple. Cloud Drive can be used to store files of almost any type, but the initial version is particularly well suited to music. Additionally, Amazon has launched a cloud music player service called Cloud Player, which works via the web or through the Amazon MP3 app on Android devices.

"We're excited to take this leap forward in the digital experience," says Amazon vice president of Movies and Music Bill Carr. "The launch of Cloud Drive, Cloud Player for Web and Cloud Player for Android eliminates the need for constant software updates as well as the use of thumb drives and cables to move and manage music."

Amazon is offering all customers 5GB of cloud storage for free, and for a limited time if you purchase an MP3 album from the service you will get 20GB for free. Additionally, MP3 music purchased from Amazon and downloaded directly to Cloud Drive isn't held against the user's storage allotment. (You can download your music to a PC, Mac, or Android device at any time as well, of course.)

Amazon is also offering additional storage for an annual fee: 50GB of storage costs $50 per year, for example, and the highest-end plan—1,000GB (1TB)—costs $1,000 per year.

Customers are free to store virtually any file in Cloud Drive (as long as individual files are 2GB or less in size), but the service is currently very much oriented to music. So although there is an automatic music-uploader application available for Windows, users who want to store documents, photos, or other files will need to manually upload them and then keep track of ensuring that new files are uploaded in the future. Presumably, Amazon will add folder-monitoring capabilities for non-music files in the future.

Although other companies offer cloud-based backup and file storage, few of Amazon's size compete in this market. Microsoft, for example, offers 25GB of free cloud-based storage to consumers through SkyDrive, but it does everything it can to make that storage difficult to use and access, and it has no plans to offer paid tiers of additional storage. Microsoft representatives have told me that the company isn't interested in such an offering.

For its part, Google currently offers a little-known storage service that is attached to its user accounts. But it's aimed primarily at photo storage through the company's Picasaweb service. Google also offers a Picasa application for Windows that can semi-automatically copy PC-based photos to the company's cloud storage. Google doesn't currently offer any music capabilities like Amazon, but it is rumored to be working on a Google Music service that could ultimately compete more directly with Amazon Cloud Drive. And Google's pricing is much, much lower than Amazon's: For $50 per year, you get 200GB of storage (compared with just 50 from Amazon), and 1TB is just $256 per year—one-quarter the annual price of Amazon's similar offering.

The wild card here, however, is Apple, which has been rumored to be working on a cloud-based music service since it purchased Lala back in 2009. In recent weeks, these rumors have suggested that this budding service will be bundled with Mobile Me as an Amazon-like digital locker. Apple should announce its plans by June, insiders say.

I'm currently uploading my music collection to Amazon's servers and will be experimenting with other file types as well. Expect a full write-up on the SuperSite for Windows by the end of the week.