Here's my selection of free/cheap stock photo sites:
http://sxc.hu Free
Up to 1,000 images for some keywords. Search by keywords, topics, shapes, colors...
http://istockphotos.com $1-$3 depending on an image size.
http://stockxpert.com $1-$20, the site like sxc.hu.
http://Fotolia.com $1-$3
nice accurate findings after enering a keyword. Good site.
http://Comstock.com Free and paid
http://Photobox.ruNice Russian site, prices vary much.
http://Jupiterimages.comProffesional site. Very detailed search.
Registering needed to see the prices, I hope not expensive.