Is there any sort of application that will just take whatever audio happens to be playing on a PC and stream it to a UPnP Client? For example, you could just run the app, and then play music from anything....WMP, iTunes, VLC, whatever...it would likely just use the Stereo Mix "device, and then on an XBox 360 you could connect to that stream and it would just play it back.
I know this should technically be possible... and I was thinking of trying to create something to do this, but I don't want to recreate something that already exists.