Have you been to Boston recently? Ridden the T (as the subway there is called)? A while back, they switched from friendly little nostalgic tokens to awkward tickets and commuter passes called Charlie Cards. Living out in the sticks of central Massachusetts, I don't spend enough time in Boston to bother with the Charlie Cards, but the tickets are just not terribly pleasant. They aren't awful, but for some reason, I find the machines that dispense them to be counterintuitive. They just irritate me. They also offer you student rates, only to discover that it takes a super-secret student card issued only by the Society of Freemasons in the dead of night to get the student discount. They even have staff floating among them, helping out wayward travelers, much like the self-checkout lines in grocery stores that never seem to save anyone any time: a bad sign for sure.
The Washington, DC Metro has used tickets for a long time and, unless they've changed drastically since I was there last, are entirely friendly. The tickets carry a running tally of the value remaining on the card (the Metro charges different fares, depending on distance traveled) and the machines take your money and spit out a ticket. No Metro staffers waiting to help, either because DC is a cold, unfriendly, hostile place to live, or because they're so darned simple, even George W could make his way through the Metro by himself.
That being said, I feel the need to applaud the MIT students who posted their presentation on vulnerabilities in the Charlie Card system. This is Boston and Cambridge in 2008, land of open source, brilliant minds, and tolerance for just about anything, except bad computer interfaces and poorly designed information systems.
Post away, kids! Judges, slap them on the wrists if you must, but then go and buy a T ticket. Let me know if you don't think they have the right idea.