You should probably do a search of the discussion archives; you'll find lots of people have been playing with this stuff in the past. To summarize: The USB chipset in the 770 is capable of host or device mode, ie: OTG. However, actual proper OTG support would require both an OTG connector in the 770, and that the 770 supply 5v power to its USB port. Unfortunately, it does neither. If you want to use the 770 as a USB host, you'll need to provide 5v _to_ the 770, _regardless_ of whether the device you're hooking up has power or not. In other words, AFAIK the 770 itself _needs_ 5v to turn on its USB. Numerous people have built various kindes of devices to supply 5v to the 770. You can build your own using a regulator, or you can use a weird dual-headed USB power cable designed for hard drives to suck power from some other computer.