Anyone wired a self latching or other type of anti-theft kill switch ?

I used a simple toggle switch that cut the power to the starter, hidden under the dash. Took me a while to get into the habit, but I would switch on to start, then back off once running, granted that the car could still be hot wired or towed, but I always felt that if someone wanted something bad enough, they will find a way, no matter what I do.