Google Docs & Spreadsheets is a great service for collaboration. With the quite recent introduction of Revision History in spreadsheets, it became even better. However, there is one thing that really annoys me - when working on a spreadsheet with several sheets and you want to see what your collaborators have changed, you can't see which sheets were edited but have to manually step through each sheet and look for edits. It takes time, a lot of time...
That's why I sat down this weekend and wrote a Greasemonkey script that puts editors' colors on the sheets they have edited. While at it, I also made the sheet switching quicker and made it behave more like an ordinary diff viewer by putting the previous version to the left of the current. Have a look at the images attached.
Tested on Firefox 4 on Linux and Windows with Greasemonkey 0.9.5. The current version doesn't work on Chrome, but it's on the TODO-list.
As usual, I don't mind a small donation for this work that is provided absolutely free :-)