A friend of mine showed me a site called Mayang.com a couple of days ago. They have some of the best selection of free textures I've ever seen on the internet. The images don't tile (which is easily taken care of in Photoshop), but most are extremely high-rez (some are 2MB in size), and are taken at a relatively straight angle.
Here's a texture I made using one of em:
http://i79.photobucket.com/albums/j152/RotatorSplint/spawn_spot_test0002.jpg
I figured some of you custom-content junkies out there (like me ) would wanna check it out. Enjoy.