Forbes has a piece on a new technology aimed at finding cell phone theives–at least the ones that are silly enough to use the phone shortly after lifting it.

” Why not start with embarrassing the thief? Anytime a stolen cell phone is used, a computer would automatically call the same number just after the thief’s call is over. A recorded message would say: “This number has just received a call from a cell phone that was reported stolen. At the tone would you please identify the caller.” We think that this is better than just turning off the phone (at least for a short time) so that the thief can be outed and the trail can be marked.”

Also, phone makers are ready to launch techology that would make it possible to deactivate a phone despite SIM card changes (though this could be used by the carrier to keep you on their network…).