if you're sitting at a pc and wanting to drip, go with the Puresmoker passthru. the higher volt will give great taste, and reviews show it's a sturdy device that should treat you well.
i'd say get a wall plug USB port though, and to not use your PC for it. others will disagree.
THIS. (I imagine). I got IMPATIENT AS HELL WAITING FOR MINE TO GET HERE HINT HINT so I drilled a friggin hole in a dead logitech quickcam, put a phone jack in it, and reused the button and "YOU ARE BEING RECORDED" light emitting diode. God I feel cool.
Either way, I'd imagine you'd get the same total USB voltage from the puresmoker unit THAT I'M HOPING GETS HERE TOMORROW. : )
And it will be amazing however....
I'm lead to understand that the USB interface only puts out .5 amps, and that one of those universal powerpack dealios for ipodphonemackangaroos puts out more, and will provide a more satisfying vaping experience.
Hope this helps.