I like RuBher's razor wire idea
BUT I can see why one wishes not to call the insurance company. They'll jack you for anything these days. But to be fair, mine actually tells me when I should or should not report soemthing officially through them - like when I hit the dumb broad this year at WalMart. It was her fault and my insurance company told me to try to handle as much through her insurance company so my deductable, accident forgiveness, etc. wouldn't be altered.
Her insurance company still held me 10% liable in the incident, basically for being there. I guess I should have died that morning or something.