The driveway alarm is on sale for 13.99 with coupon code 68837004. Its been mentioned before for triggering sound activated props, ( I can't find the thread on this). I can't tell if its the one with different channels but thought I'd at least post it.
Thanks Namrog. Bought and installed one last month to alert for Trick or Treaters. Nice idea to use it as a means of triggering sound activated props. If anyone does find the thread, please link to it.
I had bought one of these for protection at night and it was too sensitive to use. It went off every time a car went down the street. It would probably work great for someone not close to a street. Did use it to catch someone that was stealing Christmas décor though!