At first glance the service by new image search engine TinEye seems to be a great way of seeing if there are multiples of any image on the web. After looking at their FAQ I decided I liked it a lot more. You can ask for an invitation to their private beta on the main page. (The nice people at Idée even have a weblog for the project: http://blog.ideeinc.com/category/tineye/)

I like the fact that there is a FireFox plugin so you never even have to go to the main page (as long as you are logged in) to search an image. :)

I decided to give you a few examples of my own using .MISSING YOU. by evol1314.



This first image is to show the nice little right-click menu which will let me search right from the original page.


Look how many different results were found for just this one image!  141 from over 700 million, fifteen pages worth.  I only capped what was on screen at the time.

Can't wait for this to be fully released, let's hope it gets even better. :)