Useful Firefox Plugin

I was looking at an entry in Yahoo! employee Jeremy Zawodny's blog and decided to try a plugin he uses -- Aardvark. What's useful about it is that you can use it to kill off ads in web pages on an individual basis. If you want to print from a website, you just activate Aardvark by a right click, mouse over the item that you want to remove, and then press r (for remove) It disappears. There are other hotkeys which you can use -- press h (for help) when Aardvark is activated. The homepage for the actual program is here.