You dont need to do a thing actually. When you post your image on the web, for example, here at Renderosity, you also have the complete rights for it automatically.
There are also ways to copyright the entire content on a webpage.

Unfortunatly, this is of little help against art thiefs, since they dont care about laws anyway, and the only real protection against art theft is to not post anything on the web at all. Or you can try to make it harder for the thiefs to use it.

This is one of the main reasons i never post or send out any high res files to anyone, unless i see a valid contract, or i know that they are serious.
Posting the images on numerous galleries on the web also helps. Not only because people often recognize images that are stolen, but you also have the posting dates, which is another proof that the images are yours.
Another trick is to "hide" your name in the scenes. Small billboards, house/road signs, a newspaper laying around, things like that.

Message edited on: 07/08/2005 17:21

Rudolf Herczog
Digital Artist
www.rochr.com