isn't greasemonkey against googles TOS?
<<I could have hacked something together with Greasemonkey or a Firefox extension>>
http://googleblog.blogspot.com/2006/05/googles-20-percent-time-in-action.html

I don't think so, Mihai Parparita (one of the Googlers involved in Google Reader) has done several great Greasemonkey scripts for GMail and Google Maps that can be found at http://persistent.info/archives/hammers/index