Chrome: If you need to keep an eye on shared documents but you don’t want to stare at an open Google Docs pane, WatchDoc monitors your shared documents for changes and notifies you from Chrome toolbar.
Install WatchDoc, log into Google Docs (there’s no configuration or credential storage necessary), and WatchDoc will monitor all the shared documents in your Google Docs account. When ever someone changes a shared document a red push-style notification will appear on the WatchDoc toolbar icon. Click the icon and see a change log that includes the document name, time, and username of the individual who modified it.
WatchDoc is a free extension, Chrome only.