RedGage

I have created an account on Deviant Art and I am absolutely hooked. It is filled with tons of pictures in all different types of categories. I have found some pretty amazing artist on this site, it is an excellent place to get inspired. It is sort of like a flickr, but a lot easier to find stuff.
They also have store where you can buy fine art prints, posters, greeting cards, coaster, etc of artist all different types of artists.