Puttyboy I like tape as well. My first tape to use is the scotch removable, then regular scotch tape, Framer Tape (from United, not Framer 11). I also use a glob of ATG and roll it around the ATG to pick it up, kinda like using a wad of bubble gum to get the residue of the exploded bubble off your face! Use what caused the problem to clean up the mess!
Last resort would be Lighter fluid, works great! Also works to remove wax pencil off the plexi.
BTW the tape works to get adhesive off the front of posters and photos, but be careful it doesn't stick too well to the photo! And according to CSI and the FBI it can take fingerprints off of photos. (I can attest that it works too!)