Google announced yesterday a new developer tool called Google Gears that will allow Google and third-party developers to take their Web applications offline. The implications of this move are huge, assuming Google can pull it off, and represent the company's most obvious attack on Microsoft's desktop-oriented software dominance thus far.

Imagine a future in which Google services such as Gmail, Google Calendar, and Google Docs & Spreadsheets can be used offline. Today, these services are tied to the Web browsers in which they run and require an active connection to the Internet. With Gears, Google is attempting to sever that requirement. Soon, virtually any Web application can be made to work offline, Google says.

As a proof of concept, Google announced that Google Reader, its Web-based RSS reader, is now using Gears and can be accessed offline. According to the Google Reader Web site, Google Reader can now cache the 2000 most recent subscribed items, allowing you to read them offline.

Google isn't alone in pushing Gears as a solution for offline Web applications. Partners such as Mozilla, which makes the popular Firefox Web browser, are also helping Google with the technology. And because it's being released as open source, Google expects many third parties to jump onboard, extending Gears in unexpected and innovative ways. The company probably has a point: If Google can make Gears work, it may have just erased the only serious pain point for Web-based applications.