ZFT: I don't know anyone who thinks it is a good idea. I don't understand why the airlines should want to do it.
Bangkokeasy: I used one once, for a joke. I called the mrs as I was flying home one time, it was quite funny, where are you says the good lady, 35,000 feet over India responded I. Quite funny until I got my credit card bill that is, USD25 for a 1 minute joke....