This concept is so simple, yet so BRILLIANT. I wish I had thought of it. The geniuses behind Baseball Card Vandals (slightly NSFW: wiener doodles like this one on Bill Russell) take baseball cards and deface them with a Sharpie (no Photoshop used at all) to create hilarious new works of art. (Like when you used to deface your Pee-Chee folders in school. Did I just date myself?)
But don't take my word for it. Click! Go! Laugh your ass off.