Well I just tried using mine while it was charging. I have it and all my other USB style PV chargers plugged into a powered USB mulit port hub (not the PC). I tried vaping while it was plugged into the USB hub and viola, vapor! So yes, it works while charging.
I have not tried this plugged into my PC or usb car charger yet. My PC has no open USB ports at the moment... but since it worked off the USB hub I would imagine it will work off any USB port.
OMG!! This is a HUGE feature! This could be the last PV you will ever need. Looking forward to that video review Jackal.