Dreamstime.com was my first online stock photography agent. I was slow to add files at first. After acquiring a new digital camera however, my uploads have increased as I decifer what is stock oriented work and what's not. If you are looking for images in a wide variety of styles and themes... this is a good place to look. You would be surprised how many odd requests for specific subjects in certain situations you get in advertsing and Dreamstime was there to the rescue a large majority of the time. They offer many types of licensing options from Free Stock, Royalty-Free, to Editorial usage. They are probably one of the larger and most reasonably priced stock photo agencies on the net currently.