An often overlooked item in your bike is a pair of tweezers.  There are fantastic for pulling out bits of wire from your tires when you flat, saves on finger cuts or a ruined tire. Also, they can be used to pull out your splinters or in a pinch can substitute in for a small flat head/phillips screwdriver for your bike.  If your buddies are late for a ride you can catch up on your personal grooming and tame your uni-brow or noise hairs.