Is it one of those RAM-Mounts (i.e. with the ball joints)? Does he use the bike for commuting or quick trips to the local fast-food joint? If yes, maybe a cup holder would be a fun gift idea. Not sure how practical they actually are, because i don't have a mounting point for it on my bike.
I've heard good things about this cup holder from some of the guys over on /r/motorcycles
or this