That is sooo wierd!!! I used to have Nextel and while driving, I could always tell when I was about to get a call. I would hear this crazy static thru the speakers for my radio first, then 1 second later, the phone rings!!! Luckily, I haven't experienced any problems while flying, but I also don't recall if i've ever actually received a call while in the air or starting up on the ground. Needless to say, I won't take any chances and I strongly recommend everyone else do the same. Yes, it'll hurt to loose a model, but it can be replaced. It's the safety issue i'm most concerned with, property damage, injuries or worse, etc...
Personally, as with driving in many states, I think cell phones should be banned from flying fields as well. I'm sure many of you will chime in on this one.

Richie