Gives Power to the People Rated 4 out of 5 stars

Greasemonkey is a way for users to take control of their web experience. Using JavaScript, you can have the final say on how a web page renders. Great for adding productivity enhancements or blocking unwanted page features.

There are some issues with script security and deployment/versioning that you should be aware of, but otherwise its thumbs up.

I wrote a series of blogs on Greasemonkey:

http://dev2dev.bea.com/blog/plaird/archive/2007/08/greasemonkey_in.html

that covers my thoughts in much more detail (pardon the self promotion).

This review is for a previous version of the add-on (0.7.20070607.0).