These are their own art form. Here are a couple of images I just made with some random interweb pictures and Photoshop proficiency:
If you have any random Photoshops lying around, post them here.
By the way, I don't really know if this thread should be here or in the Lounge. Mods, if I posted this in the wrong place, please swiftly and mercilessly move it to the right place. Thanks