Two tools in this post, plus a video to help make up for the lack of updates in the past couple days.

For these first two hacks, you need Firefox with Greasemonkey.

Once you’ve installed Firefox, you can get GreaseMonkey here.

Alright, hack number one involves styling profiles. Although there is no way yet to stylize your own profiles for others to see (keep checking back here and we’ll tell you when that becomes available), with GreaseMonkey you can colorize your own Facebook experience.
Here’s the script:
http://userscripts.org/scripts/show/3626

Second, there’s the Facebook Toolbar. This handy plugin attaches itself to your toolbar in Firefox 2.0 and alerts you whenever something happens in Facebook. No more obsessive checking every five minutes!
Here’s the link:
http://developers.facebook.com/toolbar/

Finally, here’s a video about keeping your profile secure. Don’t let yourself get hacked!
http://www.youtube.com/watch?v=B677hoo7uXA