A couple friends of mine are travelling around Asia and are actually managing to maintain a blog.
Yesterday, they were in Hong Kong and they mention this about using the public transit system there:
Of course the ticketing system is very modern and similar to the metro now. You can even use your Octopus pass, which is a card you simply scan to use on any public transport. It works much in the same way my work badge that lets me into the building does. You can add funds to it at any “add funds” kiosk in any MTR station. I love it.
Sure, that kind of pass isn’t unheard of here in the States, but it’s nice to remember that there are some cool things about public transit in the world. Not least of which is an “Octopus pass”… what a name… :)