What I've always wanted to do is install an alarm with a pager, but disable the siren, and install one of the many GPS tracking devices, and then let my bike get stolen.
When the pager tells me someone's messing with the bike, I would load up the GPS website, and see where the bike goes to. As soon as the bike stops moving, I'd wander down to the location, with a couple friends, and take back not only my bike, but call the cops and inform them of where the theft ring is located.
If I wanted to go all out, I'd park a car or a minivan near the bike with a camcorder inside to record them stealing the bike, just for evidence purposes.
But that's just me.
Later,
BC.
I didn't do it, I swear.
And even if I did, what makes you think I would admit it to you?