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!"
So WebDev511, how do you respond when someone says, "knock, knock" to you?
Are you able to bring yourself down to the level of human comedy and reply, "who's there?"
Or do you say to them, "that is not very good onomatopoeia. You should attempt to make a sound that is closer to that of a person's knuckles repeatedly impacting the surface of a wooden door"?