How can I charge an ASUS Transformer while connected to USB? Currently I'm developing with my Nexus S but would like to use Asus Transformer for that.

So far I figured that device won't charge from USB. And for me - I need to have it on USB for debugging while charged and ON all the time.

Is that even possible? How long device lives on battery when 100% on?

EDIT

I look at keyboard accessory and it looks good. It seems that I can charge and it will serve as a stand. But I'm not sure if USB in keyboard will work for debugging?
The Asus Eee Pad Transformer uses a USB 3.0 cable. I've seen noises elsewhere on the 'net that it will only charge on a USB 3.0 socket. This is likely associated with the extra power only available on USB 3.0.