Firefox Plugin - Greasemonkey
Cool
Firefox Extension from
YoungPup:
Greasemonkey
Greasemonkey is a Firefox extension which lets you to add bits of DHTML
("user scripts") to any webpage to change it's behavior. In much the same
way that user
CSS lets you take control of a webpage's style, user scripts let you
easily control any aspect of a webpage's design or interaction.
It's kind of a more organized approach to site-specific bookmarklets. I've
done some right-click context menu extensions in IE to work around problems /
annoyances in intranet apps before; this would be perfect for that kind of
thing.
Read more here
Download here
There are already some useful scripts
available:
Screenshot:
Source: YougPup