Her's an easy way to mount a stylus on the side of a bookcase frame that leaves no marks and is easily removable if you want. The key is to get some 3M Dual Lock - it's like HD Velcro but it "locks" in place when you push the material together - it is extremely strong and we mount marine equipment upside down to the ceiling using it. Google it -cheap in in 2 inch squares.The DL comes in clear so it is unobtrusive.. Cut a 1/2 inch "sliver" and mount it on the pen...clean the pen with alcohol for a good grip - and the adhesive takes an hour to cure - but comes off easily with no residue. Do the same for the frame. Press hard. Keep the pieces very small so the pen comes off easily. "Roll" the pen off to the side to remove it, pulling straight up can loosen the material.