Google Docs is finally getting offline access. Zoho writer offered offline functionality long back using Google Gears extension. But Google took this much time to offer offline functionality via Google Gears.
Starting from today users will get the offline access to Google Docs in phases like any other Google update. So if you don’t see offline access it wait for few weeks you will get it, when you get the offline access you will see “green arrow” like you see in Google Reader (if you use it). You need to have Google Gears extension installed in order for this to work.
You can use this feature to access and edit your documents offline, and when you turn online changes you made to the documents will be synced to Google servers. If two or more people are editing the document offline, when they come online it will show a message saying there is a conflict of versions in the document. This is pretty useful if you have a collaboration team which works simultaneously.
Currently offline feature is only available in Google Docs, Spreadsheets and Presentations are not offered offline at the moment, you may expect to get these also offline in near future. Source: Google Docs Blog
This feature available only in Docs, Google seems to be updating only docs.