Sorry for the double post but I thought I'd point out that if a would-be intruder applied say 12V or so to a few of the keys on the keypad the poor PIC would writhe in pain a bit then squirt some output to the garage door relay and Bobs your uncle... you're in. (assuming there are no measures taken to stop excess voltage being applied to any of the pins). I'm thinking I'll put a bunch of zeners inline.