long range pager system

You can get a 5900 which has a 1 mile range.  I use mine all the time.  I live in NYC and you can imagine all the building around.  As for "unlimited range" you can get the GPS tracking system by Viper 210V(DEI).  This would not only track your vehicle but will also arm,disarm, and allow you to turn on your car from wherever you are with a simple phone call.  It will also alert  you if your vehicle is being driven over a certain speed limit in case you lend the vehicle out.  Only down side is that for the 210v you would have to pay a fee every year but its far better then LOJACK and ONSTAR.