Let the hive mind of Engadget get that for you.
"I am looking for a device that will stream sound from one source to several recipients. For example, I want to stream sound from my TV or stereo to my phone or MP3 player that has radio and Bluetooth capabilities. I have looked into radio transmitters and they seem like a decent choice, but I can't find one that uses external power (USB or from the plug) and I would want one with a transmit range of around 50 meters. Thanks!"
Think about it - if there is an average of 2 people using the service on a transcontinental flight they basically have a dedicated sattelite uplink and all of the air/ground support that goes with that factoring into their price.