Wither the Mobile to Mobile network

Every cell call you make goes to a tower; then it is switched to your called party who may be seated next to you, or at least a lot closer than the tower. Just like the FRS walkie talkie radios why not drop the tower from the callpath. Even Nextel's walkie talkie style push to talk service is through towers. A lot more robust cell network would use mobile to mobile radio channels, and this would give a lot more capacity overall, taking the load off the tower - which would only be neccessary for calls beyond your own handset's range. In fact, if it weren't for billing and wiretaps the phone company could be taken out of the equation for calls within your handset's range.