From the site:
As a user, you gain access to more than 400,000 high-quality, hand-picked stock photos and graphics — all free! Need a wallpaper for your desktop or an illustration for your blog? Want to spice up your commercial website design project? Looking for inspiration? You’ll find everything on SXC quickly and easily.
Editor’s note: If you are seeking only free images, double-check where you’re clicking, so you don’t accidentally end up on the iStockphoto site. iStock results are returned at the top and bottom of every page, with the freebies in the middle.