PlaneImages is the Flickr of aviation photography!

Just hover to the search page and look at the possibilities—you can search by aircraft, by airline, by airport, etc.

Glorious.

My only gripe is that one can't (yet?) search for pictures under Creative Commons licenses.

You can add your own, so get on with it, they need more pictures!

Glorious indeed. (image credit: Joseph Madden, Goodbye Discovery! on planeimages.net)