Photolibraries that fit into the new wave of microstock web sites include istockphoto, dreamstime, shutterstock, stockxpert, big stock photo and Fotolia. These photo libraries offer images from just $1 for web based images (images that are small enough to really just be used on web sites).
iStock is currently one of the most popular microstock photo libraries and has quite a strict moderating board, so you’re not going to get sub standard images on there. You can find photos, illustrations, vectors, animations, videos, and soon to be launched - audio files.
Fotolia arrived on the scene a little later but is doing really well and has a nice clean interface.
Shutterstock seems a little clunkier in the design of the site, but it has an enormous catalogue of images.