When my friends visited Paris, they asked me about the "cool bubble cars" they kept seeing everywhere; they were talking about the Smart Car, which I think looks a bit like a rollerskate. They've had them in Europe for some time- completely logical if you've ever tried to navigate the cramped 19th century roads here. They've also been selling them in Canada for a while; in fact, Claire's mother owns one. It doesn't exactly look safe to me, but Claire's family are all gearheads and they claim that it's nearly impossible to roll and that it will hold up in an accident because its built with the same sort of skeleton that they use in racecars.
Anyway, they're finally selling them in the US, which is good because someone seriously dropped the ball on fuel efficient cars there. If the Smart Car people can convince Americans that they won't be pulped in an accident in one of these things, I think they'll clean up in the states too.