Spare fuses and bulbs are handy. A length of pipe to slip over the lug wrench handle if you don't have a better lug wrench, I once use the free tire roataion service that came free with my new tires and then I had to jump up and down on a 6' pipe on the end of a wrench to break the lug nuts loose, never again will I let anyone rotate my tires.
If your not stuck in a front wheel drive a spare belt is handy because you can change modern ones without tools, front wheel drive you usually have to move other things out of the way though.