http://www.i-am-bored.com/bored_link.cfm?link_id=14019
Since a lot of my flist uses Firefox, here are some extensions you might like.
Web Developer
Ebay watcher
Colorful tabs
Fasterfox
Periodic Table
story monitor
LJ hook
LJ friends checker
Nanowrimo Meter
Click Weather
And I shall end this link-fest with something that made me smile instantly when I saw it...
Beer O'Clock.