Google Docs now features a color-coded revision history and better time stamps
This new tool replaces one of the worst and most-clunky features of Google Docs -- and it's about time. By default, the interface clumps revisions together, so that large documents aren't completely unreadable (but you can click 'Show more detailed revisions' to see every revision). Timestamping of revisions is now much clearer, and enabled even for very old document changes.
The blog post says there's more to come, too. It's just a shame that it doesn't work with existing documents!