I don't know if it's common knowledge, but http://www.af.mil/photos/ has a great archive of extremely high resolution pics. On the right you can sort by quite a few categories... if you're doin a modern aircraft (like somethign from Iraq) this might just be the place for you!

That F-16 sure is a sexy bird

Thanks for the link. The Navy has a similiar website at http://www.news.navy.mil/view_galleries.asp