Surprised there's not much mention of Imagekind... besides one commenter. For people who have no readymade audience that will go to their particular site, I think it's a decent option.
Also
cacklin, the free option may be just what you need. You can upload a few shots for free. I did it a few months ago and have just five shots up there and someone bought 8 prints of one shot the other day giving me a profit of about $200. Granted, this is very likely a one-off thing, I was mildly shocked, but for no work required other than uploading once, it's really not a bad deal!
My gallery is at
http://photoshimona.imagekind.com/