I cruise a couple of bike sites and i've also seen a disturbing increase in the amount of posts on bike thefts.
The growing concern prompted me to look up GPS enabled alarm systems.
I found this: http://www.unitracking.com/
This spring (I'm in the northeast), I'm going to seriously look into this service - as far as pricing and any insurance breaks I can get from it.
It's easy for some to say, "ah, just have the insurance replace the stolen bike.." but after spending time, $, and effort to get it just the way you want it, damnit - I don't want to replace it, I want my baby!!!