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!"
How long does it really take to build one? An hour? Considering the money that would be saved, it's well worth it.
My first build took me about 2 horus or so on teh hardware side and another 2-3 hours on the software side. Definitely saved money and it was a good learning experience. The key is to do the research on the components beforehand to make sure you get exactky what you want. Got all the parts through Newegg.com