Roger Worden wrote:
I've seen a couple of references to someone not wanting us to use
cell
phones while gliding. I haven't seen the reason... what's the
rationale?

In the US there are FCC regulations prohibiting the use any aircraft -
from a FCC web page: Section 22.925 of the Commission's rules, 47 CFR
Part 22, provides that cellular telephones installed in, or carried
aboard airplanes, balloons, or any other type of aircraft, must not be
operated while the aircraft is off the ground. The FCC concern is
interference they may cause.