GreenPlug will show the first environmentally-friendly DC power hub at the CES 2008.

GreenPlug will show an Universal Power Protocol (UPP) Chip called the GreenPlug.
GreenPlug wants to get rid of the device-specific external DC power supplies and replace it with an intelligent universal one. To optimize the power consumption of any connected device to GreenPlug, the power supply is 'talking' to the gadget via a protocol called GreenTalk.

GreenTalk is a secure, digital protocol for real-time communication between devices that require power and their power sources. GreenPlug enabled DC power hubs are able to simultaneously power multiple devices, each with its own specific voltage and power requirements.
GreenPlug will preview their technology at the CES 2008, which means they are not ready for production yet.
More details on the GreenPlug site.