Firefox Hacks
Wired News: The Firefox Hacks You Must Have is great collection of extensions that you can add to Firefox to give it more bells and whistles. I have had conversations with people who don't understand that the glory of Firefox is in the customization. Many people who try vanilla Firefox see it as exactly the same as IE. Not!
For those who may have thought that, take a look at these add-ons for Firefox, maybe try some other ones as well, and discover how great it is to have a browser that you yourself have designed, that works the way you want it to.