Zoho announced today that it's making read and write functionality in Zoho Writer available offline using Google Gears. Most of the tech commentary focuses on the office aspect of this, which is great because Zoho is really pushing the boundary of what online office applications mean. As Read/WriteWeb notes, this is a big leap forward from what other office RIAs are providing.
But the biggest thing for me is how they're using Google Gears. Google Gears is a great idea but it so far seems to be underutilized by Google. When it first came out, the only application that supported it was Google Reader. When people really started using it they quickly ran into the wall of no out-of-box support for synchronization. The synchronization issue is the single biggest issue for RIAs today. Very, very few applications have figured out how to truly take RIAs with complex data offline because being able to synchronize changes is a hard technical problem to solve. Zoho has always focused on collaboration and in reality, that's one of the major value adds for these types of RIAs. They can't compete at a UI level with Microsoft Word so ultimately it's about creating other web-centric features to get ahead. There seem to be some bugs to still work out, but Zoho has built a framework for synchronizing collaboration changes with Google Gears which is very cool.
I'm not sure if this is a problem Google is working on, but you would think this type of support would be added to Google Docs in the near future. Will Google open source that synchronization framework and add it to the Google Gears project? Microsoft is there and Adobe has some of that functionality with LiveCycle Data Services. But right now there isn't a clear winner for the Ajax mind share when it comes to synching rich Internet applications.