you can import pics from the multiplayer options menu. the pic has to be 256x256 or something though. THere is even a tool for editing pics and saving them as custom sprays for valve games...just google.
If you're using GIMP save the pic as a .bmp because it does something to .jpg files that make steam think it's corrupted. --- Sir, you don't understand. I'm a professional beach bully. http://i247.photobucket.com/albums/gg148/Krauser_owns/krauserownsaf9.jpg