Frequency modulation instead of network stacks turns out to be a pretty cost effective way of getting your house set up for internet radio/streaming. I recently purchased this device which is a low power FM transmitter built by a company in South Africa called EDM Design.
After minor assembly, I plugged it into an 3.5mm to RCA cable converter (that has a handy rheostat built in to manually adjust line volume) which I connected to my computer’s line out jack and I’m on the air with RadioScience. I can broadcast any stream (DRM or no) to all the radio receivers in my house, which is a lot cheaper than buying these Wi-fi kits for sending streams to stereos (you have to buy new hardware for every new receiver). With this system, any FM tuner in your house is now internet ready! Plus if I want to add another station/stream, I just get another FM receiver which is hardly a cost at all. Sound transmission is good and range is about 100 meters through a couple of wood framed walls, though you’ll want to play with the volume/transmit adjustments inside the device after you pick which frequency your home-brew station is going to use. Can broadcast on any FM station from 97.x to 107.x and it’s illegal in the US to broadcast over an existing station (and you’re actually likely to get caught and fined for this). Broadcasting low power FM over unused spectrum is probably legal in most parts of the US, at least for now.
The device is shipped in kit form because the FCC won’t allow assembled transmitters into the user, it was extremely easy to build (just insert four IC chips into their sockets, no soldering). EDM has great customer service and Science recommends them to you.