http://commons.wikimedia.org/wiki/Co...aces/Panoramas
^ that's full of cool pictures. Also, I took this pic the other day:
http://commons.wikimedia.org/wiki/Im...fly_Cocoon.JPG
And this is my only featured picture on wikimedia commons:
http://commons.wikimedia.org/wiki/Im...bug_aphids.JPG
Generally if you look around the features pictures on wikimedia commons and/or wikipedia you can find some pretty awesome stuff.