The problem is that the vast majority of personal electronic device in use today were created long after most of today's commercial aircraft were designed. So the appropriate question would be "would the manufacturers of personal electonic devices produce a device that could bring down an airplane?" I have a feeling the makers of PDA's, cell phones, etc. put a lot less thought into that than do the aircraft manufacturers like Boeing, Airbus, etc.

This is not to say that I think cell phones, PDA's, etc. are likely to be dangerous to aircraft. I'd just want to know that adequate safety testing has been done before passengers are allowed to start using whole new classes of devices (and I believe this is the case today). Just because we don't know of any problems doesn't mean the devices must be safe to use, and when my safety's at stake, I'd rather err on the side of caution even if it means that I can't be text messaging people all the way from DEN to IAD.