http://www.miningunited.com/index.html - Buy a share in a mining server and get paid out a share of their earning.
http://coinofmidas.com/?ref=Chrithu - A nice looking click ads site. Looks fairly new so not much ads yet. If you do not like refs delete the "?ref=Chrithu" part when using the link.
http://www.bitvisitor.com/?ref=1Gb9Sc9t9KtU7tZKrzktSSveBA3LCY6Q12 - One of the classics. It's quite simple you leave the add opened for 5 minutes (even in background) and get paid for it then click on to the next. Again if you don't like to refer me just leave the ?ref part out of the link.
http://www.thebitmines.com - Earn bitcoins by playing minecraft. Takes some time but at least you have fun while doing it. You need to shell out 2$ to get in though, which are of course also payable in bitcoin.
