"lo-jack"/tracking system ?

[RadioFlyer]

I'm not familar with the system they put in cars, but one of the reasons I only commute to work instead of living more car free is I'm afraid of my bike being stolen (again).

I've read posts here about using a multi-locking system and while that probably works really well, I'm still hesistant.

So, are these stolen "vehicle" systems something that can be used on bikes?

I'm thinking if it's small enough, attaching it to the bottom of the seat-post and having it sit inside the seat-tube. Does something like this exist? If so, expensive?

[lyeinyoureye]

DIY (http://www.makezine.com/blog/archive/2006/04/diy_cell_phone_tracking.html)

[Smallwheels]

Lojaks cost about $500-$600. They don't work in all areas of the US because local police departments must buy the equipment to put in their patrol cars and subscribe to the service. The Lojak site gives you this information. You can input your zip code and they will tell you if they have the service in your area.