Hufty, before you do that, have a look at RugMunchers' post and then imagine a similar device that does not need a PC and will transmit from any device (Not just PC/Mac) with a 3.5mm stereo headphone/lineout socket to any radio/ car stereo, etc. and does it more cheaply. Have a Goggle at Google for the Arkon Soundfeeder and don't look if more than 15 quid.
Excellent piece of kit. I use it for many things, like putting the GPS voice directions on my PDA through the car stereo, or ahem! Playing internet radio from same PDA through the Hi fi... The last I have just tried as a result of this thread and it is Brilliant!
Conan