
Contactless AND with USB
To people asking why should a contact-less card need a USB connector.
The reason is simple: you use the contact-less side of it to go through the gates at the station, like the Oyster card and you plug the card into the USB port your own PC at home to recharge it!
This is quite a good idea as most PC's have USB ports these days but very few have smart card readers (and even less RF-ID readers).