The adblock crew updated their Firefox extention to block ads. Ive been using it for a while now and this plugin really rocks! If you like Firefox...Im sure you are gona like this one. Just download at crapcontrol.com

Description:

Tired of ads?

If you're tired of all the intrusive adverts that are increasingly taking over the Internet, Adblock is for you. Using the numerous free filter repositories available on the net and the intuitive blocking tools, you are able to customise your Firefox so that the most annoying ads are not displayed, thus leaving you to browse safely and to enjoy your Internet experience. Once installed, it's a snap to filter elements at their source-address. Just right-click: Adblock: done. Filters use either the wildcard character (*) or full Regular expression syntax. Hit the status-element and see what has or hasn't been blocked.

*** You need Mozilla Firefox to install this plugin ***

Official site: Adblock.mozdev.org