Just go crazy covering that old magnet with some fun washi tape. I picked up my Washi tape at The Dollar Tree. They have a bunch of styles for only a $1 a roll! Score!!
Make your pen stand out from the rest using Washi Tape! Just take the inside ink part out and wrap the Washi Tape around vertically. Put back into pen and when you lend your pen they'll know it's yours! You can also write your name or whatever you'd like on the tape:)