With all this talk about USB ports on tablets, what exactly can they do? I mean can the tablet play as the USB host, so lets say I could....plug my phone in via cable using PDAnet and have the phone charge while tethering to the tab? Can it read external hard drives? Can I plug in my digital camera and transfer pictures? I am assuming connecting keyboards/mouse would work? Just wondering because I don't know exactly what the USB would be useful for if it couldn't do the above. If it can do the above...that would be amazing.