Yeah adblock is an awesome extention for Firefox but since im using firefox beta 2 (deer park) it wasnt totally compatible for me and would screw up 6 out of 10 times.
But they are back with Adblock Plus! and it works like a dream. It has one extra feature i have noticed which is the hide div and hide iframe function as opposed to the previous version having only the hide frames option (which is still there ;))

You can get the latest version from from here and if you havent got your firefox beta 2 (and want to even tho it is a beta) then you can get it from here

And if you are too lazy … here are the most common options
Windows - US English
Windows - GB English

Windows - French
Windows - Spanish (European ??)

People using other languages or other operating systems like Mac and Linux can get it from here