I'm an honored beta tester! 
I received a USB "bat" for my 901 from Cash a few days ago, black with a red led. I've been using it at work on my old-ish computer with a USB 1.0 port. It does not have a manual switch, so it activates just like a normal bat.
So far, so good. Used it all today and Yesterday at work. It performs just like an almost fully charged bat - all day long.
Probably would work even better with USB 2.0...
The only dicey part are where the threads connect up to the atomiser. They're a little loose and wobbly - but no big deal. I've been assured this will get fixed very soon.
I'm told they're going to available from PureSmoker.com - Your #1 Source For ECigs, Parts, & Accessories! within the next 24-48 hours for the 901, pen, and peewee.
PS: Before you even ask, I don't know the costs.....
I received a USB "bat" for my 901 from Cash a few days ago, black with a red led. I've been using it at work on my old-ish computer with a USB 1.0 port. It does not have a manual switch, so it activates just like a normal bat.
So far, so good. Used it all today and Yesterday at work. It performs just like an almost fully charged bat - all day long.

The only dicey part are where the threads connect up to the atomiser. They're a little loose and wobbly - but no big deal. I've been assured this will get fixed very soon.
I'm told they're going to available from PureSmoker.com - Your #1 Source For ECigs, Parts, & Accessories! within the next 24-48 hours for the 901, pen, and peewee.
PS: Before you even ask, I don't know the costs.....