A recent story about the U.K. possibly allowing cell phone use on airplanes quotes someone saying, "It would drive me absolutely mad if the person next to me was using his phone."
Now, some people speak more loudly when they're on the phone than when they're talking to someone next to them. Those people need to learn to quiet down.
Putting that aside, the only reason to be annoyed by a cell phone conversation is because you can't eavesdrop on the whole thing. You only get half of it. You know what? Tough shit. You're not a part of the conversation. Why don't you concentrate on your own business?
As far as the safety concerns with cell phones, I'm unconvinced. I'm both a pilot and an electrical engineer. I'd be surprised if a cell phone caused any real interference with flight-critical systems. Certainly everyone's heard the DSSS noise leak into amplified audio channels, and that could conceivably make its way into the pilots’ comm radios, but I doubt it would actually prevent communication. In any case, it should be generally allowed, and each pilot should decide on a case-by-case basis when to prohibit their use.
If ON Air's system really can allow cell phones to work without interference with aircraft systems, then by all means, allow it!
Don't forget, without special help, most cell phones won't work at typical flight altitudes.