I was wondering if anyone knows of a good site of where I could find professional stock images? Or if anyone has some ideas of what I could look up?

I make manipulations with photoshop and am always looking for new pictures. I really like the backgrounds this person uses:

http://s33.photobucket.com/albums/d94/furbylp10/

I know she might do a lot of blending, but if anyone has some ideas of websites or what kind of backgrounds I could look up, please let me know :)