Stock.xchng is one of the best places to get free stock photos. And, the vast majority of the nearly 400,000 free photos is that they come with wide open usage licenses. Most only require photographer credit.
All you have to do to start downloading free photos (and even some vector graphics) is create an account. It's free and they don't send you a bunch of silly email. Just fill out the form and your off and downloading.
So if you need images, this is the place.