Via engadget.com...
http://www.marketwire.com/press-release/D-Link-Systems-Inc-861554.html"D-Link ... today introduced an easy-to-use Coax Ethernet Adapter Kit that taps into existing coaxial wiring throughout the home ... for extending a network to devices at the entertainment system and to multiple rooms without interrupting cable service.
"The D-Link Coax Ethernet Adapter Kit (DXN-221) is ideally suited for adding bandwidth-demanding applications such as high-definition (HD) media streaming, music sharing and online multi-player gaming to the home network. The DXN-221 comes with two adapters, each of which includes an Ethernet port as well as a Coaxial F-type connector for bridging the two adapters together. The adapters may also be purchased individually (DXN-220). "