I've been using this a while and I am sure I am not the only one, but if you havnt heard of it give it a try.
Basically it reverse search's using an image either on your computer or online and finds you either a higher resolution one or the page for it. Great for finding more info about a nameless pictures or finding similar pictures as well.
Also there is an extension through firefox where you simply right click on a picture your curious about and it will open a tab with a search of it. It doesnt always find something, but especially with the firefox extension its so quick to search its worth the try.
http://www.tineye.com/
