Sorry, but I hate these onboard telephones in the seats. It has happened so many times to me that I am sitting to someone who feels he/she needs to call the office, the neighbours, the kids, the neighbours' dog, his wife, her husband, etc. And of course the connections aren't very clear - so they start yelling all throughout the flight.
And did anyone notice that the new busines and first class seats on United have gotten a lot narrower to make room for these darned telephones?
Suggestion: instead of putting a phone in each seat, place them near a pantry or the toilets. Passengers can still make their urgent phone calls, installation won't be as expensive, and airlines would be able to advertise the 'widest seats' in the air!