Just found a great web site called zero friction, specifically for bouldering images. Quoting the zero friction site:
0friction.com is a site by climbers for climbers for a world of digital cameras and climbing photography. It is a place where a climbing fotog can upload his/her favorite pictures through a very simple process so that other climbers on the web can see those pictures. We do not retain ownership of your images, but we do retain the right to remove images at our discretion. Pictures of gym climbing, sport climbing, trad, aid, or mountaineering will be removed immediately, as will any image that sucks.
Just type an area or phase in the search box and zero friction serves up tons of bouldering photos. I tested it out on a few smaller areas and was impressed by the results.