In France, you can order and pay your train ticket online. For a few months now you can also print a PDF version of your ticket (technology by SecuTix). So you can directly jump into your train with this paper and you're done. The ordering and downloading process is very convenient (Well, some parts of the site do not work with Safari1.0 and that sucks). Here is a sample of the PDF:
Kokoro weblog tells us that the Japanese have finger recognition on a mobile phone to protect access to the phone.