At the second day of Google I/O which was all about Chrome, Google announced that offline editing is about to become available for Google Docs.
Edits are made offline and are later synced, when you connect to the web. Clay Baver, Director of Product Management for Google Apps demonstrated the functionality on a Nexus 7 tablet and it worked like a charm.
The feature will become available with an update for the Google Docs app later today and you will be able to test it out yourself. The functionality is only going to support regular documents initially, with spreadsheets and presentations coming soon.