Plug and play means that the drivers are installed automatically. There is no such thing as hardware that requires no drivers, and any reader will require driver installation, even with USB/Firewire. No intelligent internet cafe owner will let patrons install hardware or put files on their computers without a heavy-handed control system to prevent malicious attacks, and it's easier and more secure to not allow it altogether. Your best bet is to buy a laptop or find a place that can do it for you.

Sorry to be the bearer of bad news, but your want is simply unrealistic.