http://www.starwarsarchives.com
^It's a very Java intensive site, be forewarned.
There is a Yahoo group devoted to deleted scenes that had a lot of photos...
http://groups.yahoo.com/group/swcutscenes/
You might need a Yahoo ID to join it and see content though.
Here are some old sites that are still around...
http://starwars.rossiters.com/
http://galactic-voyage.com/Star%20Wars%20Cut%20Scenes.htm