I've got to disagree with all the folks that are saying Nokia did something wrong. Actually I think they set up the USB perfectly logically. This device is a compromise... give enough hackability to get the gadgetheads to participate but make it a mass market device.

The USB port is designed to be a mass storage slave so the consumer can move big files to the RSMMC. If the USB chipset were internally powered off the 770 battery then you would only be able to transfer files when the 770 was charged and you run the risk of draining the 770 battery in the middle of transferring a huge file and corrupting your card. It would be very stupid to make the USB chipset internally powered. It would only shorten battery life and add no functionality for the vast majority of folks who will use this device.

I don't know if the USB host capability was an accident or a little bonus thrown in for the hackers but it is definitely not a design mistake.

David