I always seem to be sitting at the intersection in my truck when two people slam into each other, so now I keep a small jump bag in my truck. Nothing fancy, just local phone #'s, a first aid/trauma kit, basic airways, CPR mouth-to-mouth gaurds, shears, infection control, stethoscope, BP cuff, penlight, surefire (LOVE that flashlight! I call it "The Daybringer." Roosters crow when they see that sucker.), small splints, tape, work gloves, knife... that's about it.