In case you Adblock users haven't noticed, the Adblock Chrome developer changed it's program a little to replace ads with pictures of cats instead of simply blocking them. He also changed the little symbol to resemble a little cat paw. With this April's fools, he tries to get users to donate a little amount so he can continue his development:

http://adblockforchrome.blogspot.de/2012/03/inturdusing-catblock.html

 ...And it worked! I just sent him 5 dollars, because I found the idea so absolutely adorable and creative that I decided to give him a few dollars for his work.

And inb4 rage users hate me for using and Adblocker: Yeah, I know, this site is funded with ads and if I block ads, the site don't get money. I'm a terrible person for blocking annoying ads. There, I said it.

EDIT: Topic closed? What the shit mods? This is just about sweet cats...

google also made a fake ad for 8 bit google maps for the nes
http://www.youtube.com/watch?feature=player_embedded&v=rznYifPHxDg