kdarling has it right,
A good example is Watsonville, Ca. You get your IFR clearance on the phone from FSS (Flight Service) and then when you are ready for take off (this airport has no tower), you call on your radio or cellphone (if the reception on the ground is poor) to NorCal, the Radar control and they will give you your release.
And the Pilot in Command determines the use of electronics on board his aircraft.
LOL!!
Now thats impressive