well, today some fucked-up individuals stole my nice brand new bike from school, while i was at school. they broke into the bike lockers, and cut the lock up. i was curious if anyone had some interesting ideas of...a deterrent, if you will. i was thinking of wiring a stun-gun into my seat, which i could turn on and off. when the would-be thieve sits down, he loses any chance of having children :D.
any other ideas?

Can you mount a device that broadcasts a signal when the motor is on? When the thief is close to your receiver you get a warning;) I thought of this for my car, unfortunately I have next to no electronic skills. But the stun gun will most likely fry your own balls if you forget to turn it off.

Ever think of taking the front tire off while your gone?This will deter all but the most determined bike theif.Use a Kryptonite lock too.

Do you carry a bookbag? take the seat or pedals with you. If looks aren't important to you, make your bike look old and fucked up. That what I did with my truck. Remove logos of expensive components or replace with cheap ones (the logos, not the components). Thieves are generally in a hurry and they are not going to stop to inpect the drive train on a rusty bike without a seat. Schools are so fucked up these days, I hope they will let you take a hex key inside. I remember kids bringing their new deer rifles for show and tell. Sure would like to go back to those days.