C'mon Tourist! Dogs are about as close as you can get to having a sentry gun! I say get a whole pack accompanied by landsharks and bear traps
Back on topic though, do you have any motion lights?
http://www.homesecuritystore.com/ezS...productID=1290
I've heard good things about this wireless security unit, it inconspicuously alerts you in the house when someone approaches it--may provide you with a few more seconds to get the drop on a bg if someone comes within 15ft of the transmitting unit. Works inside of cars too