Here are some resources:

• http://www.honeytechblog.com/top-10-websites-to-get-royalty-free-images/
• http://www.webresourcesdepot.com/12-amazing-and-free-stock-photo-resources/
• http://www.hellboundbloggers.com/reviews/copyright-and-royalty-free-photos/
• http://www.webdesignbooth.com/30-websites-to-download-free-stock-photos/
• http://www.thewebsqueeze.com/web-design-articles/40-free-stock-photo-sites.html
• http://www.hongkiat.com/blog/30-websites-for-stock-photos-and-royalty-free-images/
• http://www.webanddesigners.com/20-sites-for-free-stock-images
• http://www.instantshift.com/2009/03/03/40-sources-to-download-high-quality-royalty-free-stock-images/
• http://www.sitepoint.com/blogs/2009/03/05/a-collection-of-30-free-stock-photo-sites/
• http://sixrevisions.com/resources/40-beautiful-free-icon-sets/