How about an amateur trunked network?
 

I am interested in converting the 440 repeater
band to trunking. It would allow more folks,
not that we are seeing that much use as it is,
on the bands plus allow us to have talk groups
that would be either linked or local. In many
cases, instead of a number of repeater sites in
a county, it would be only one with multiple
repeaters on a single tower. Unlike cell phones,
there is little need for low power thus multiple
tower sites. Having to maintain a single site
in each county would reduce cost (if we can get
hams to work together, sometimes hams are too
"libertarian" thus it is even hard to organize
them for pizza and beer).

European police trunking radio is in the 400 to
500 Mhz region which is far better than the 800
Mhz trunking that is being down here in the US.