Simple Implementation, Complex Problem
The power of SQL calls to a lightweight, transparent, local database combined with ability to server http content locally make it appealing to dive into offline-enabling our web-apps. And Google Gears is open source to boot!
Data synchronization can become a very complex problem. Considerations for conflicts and concurrent updates must be made. Each operation must be tracked and timestamped for proper synchronization to occur.
Still, I predict that robust synchronization libraries for Google Gears will be developed. Google Gears has just been announced and is in “developer beta” now, which means it is intended for developers to start looking at and working with. Though it is not yet intended for production use, Google is using it in their feed reader product from Google Labs.