In reply to mypyrex:
Link works for me. All it is is an article with some info in, to summarise:
1) go to
http://www.google.com/imghp
2) click on the camera in the right hand side of the search box
3) give google your image and click search
This will find similar images around the net, hopefully including any pilfered ones.
RE: the right click thing, it's bloody annoying, as there are other things in that right click menu that might be useful. It's also trivially easy to circumvent. So please don't.
Realistically, anything you put on your website can be pinched. There are a number of ways to make that hard, but you can't stop screen grabs. Better to make sure that you put up "preview" images which are too low resolution to be worth nicking, or have a watermark etc.