The wonderful people at tineye have developed a firefox add-on that allows you to right click a photo and reverse search it.
Basically what this does is attempt to find other copies of the same photo across the net (good for finding 'borrowed' copies of your photos).
To get the add-on, in Firefox, go to add-ons via the FF menu (location of the add-on menu changes with FF versions), and search for :TinEye Reverse Image Search 1.1 : Install it and enjoy.
For more information on what Tineye is and does : http://www.tineye.com/about
Note: you will not be able to use it on your photos uploaded to AP, cause we block search engines from 'seeing' members photos, and thus tineye, cannot scan them to do a match.