Belkin must be using some sort of voodoo to be able to crank out 1000Mbps from a USB 2.0 bus that taps out at 480Mbps, but that's what they claim the Gigabit USB 2.0 Network Adapter can do. The adapter is designed for people who don't have a gigabit ethernet port in their computer (which is a whole lot of people) but who do have a USB 2.0 port (which is nearly everyone by now, I'd assume). The adapter is compatible with both PCs and Macs. Once installed, users should be able to benefit from the faster transfer speeds offered by gigabit ethernet. I'll believe it when I see it.
The adapter is available now for $45.