Zip ties
People make fun of me for carrying zip ties in my backpack. Until today, most of the situations I offer as times that they would be useful seem far fetched and possibly paranoid. But, today was one of these days.
I was in a car with a friend when he got into an accident. Fortunately, no one was hurt, but the bumper got detached and was dragging on the road as he got off the freeway. Before I had had a chance to examine the damage, I called AAA to have his car towed to a body shop.
When the driver examined the damage, he suggested that we just zip tie the bumper to the body instead of having him tow the car. Ironically, this was one of the rare times that I didn't have my backpack with me.