iStockphoto – Search Royalty Free Images and Photos
http://www.istockphoto.com/index.php

iStockphoto is the internet’s original member-generated image and design community. Get easy, affordable inspiration with millions of safe, royalty-free photographs, vector illustrations, video footage, audio tracks and Flash files. Buy stock or sell stock — or both. This has been added to the tools section of Research Resources Subject Tracer™ Information blog.