Giorgos is designing smart card lock for his USB ports. His board features a PIC-based smart-card reader that unlocks a USB hub only if the right smart-card is inserted.
What i am making here is a USB lock with smartcard key. The idea is that a phonecard reader made with a PIC micro will be able to store a number of different phonecards into memory. Whenever one of these cards is inserted into the slot, it will activate a 4-ports USB On/Off switch. If the card is removed, the USB ports will be de-activated.