The Gefen DVI Audio Extender extends your DVI and digital/analog audio up to 150 feet away from your HDTV DVI or HDMI source using cost effective CAT-5 cables.

This gadget consists of a sender and receiver unit. It supports VESA and HDTV resolutions on the video side and 7.1 surround on the audio side of things.
The Gefen DVI Extender has a data transmission rate of 12.8 Mb/s says the product page. Theoretically a wifi connection could handle this as well. So why use CAT-5 cables? The Gefen DVI/Audio CAT5 Extender has an MSRP $649.00
More details on the Gefen DVI Extender product page.