This site called "The Morgue File" is a pretty full site. Well worth checking out. The pictures are high resolution digital stock photography stated as being free for commercial or private use. Just so you know, a "Morgue File" is a term used in the newspapers for old files, to be used as reference. Check out the site:
http://www.morguefile.com/ <img src="/images/graemlins/fish.gif" alt="" />