jangel sends us to WindowsForDevices.com for news on a prototype device created by researchers from Microsoft and UC San Diego. It's a USB-based NIC that includes its own ARM processor and flash storage, and can download files or torrent while a host PC is sleeping. As a result, its inventors say, the "Somniloquy" device slashes power usage by up to 50x. The device requires a few tweaks on the host OS side save state before sleeping. The prototype works with a Vista host but the hardware comprising the NIC is based on a Linux stack. Here is the research paper (PDF).