GPS enabled Two-way radio

The idea is actually fairly simple. Take the idea of the traditional rugged two-way radio used by fire and police units, particularly the handheld units, and implement a built-in GPS system where through some mode of trigger, it'll broadcast it's position either in Morse code over the analog frequencies or a modulated digital signal in sideband. Include that with a programmable unit # to identify personnel.

Upon further thought, possibly have both transmission methods be automatic if the unit is not actually used in a certain range of time (5, 10, 15 minutes with no key-up, etc.. and it'll automatically start broadcasting it's position in Morse and modulated digital at regular intervals in an emergency)

While current Nextel walkie-talkie phones are capable of something like this with the advantage of being completely digital anyway, most police and fire departments are still using old analog trunked equipment where this could come in handy.

Or, if you want a TRULY foolproof setup, automatic constant GPS position and unit # broadcast on a modulated sideband back to the central base station where the position of every connected unit can easily be plotted on a map up to the second.