Really the only American City I can see that working in is New York, and even then it will really only work if you stay in Manhattan all the time. I think everywhere else you at times need to go much faster than 35MPH.
I read about Better Place about a year ago and thought it sounded very neat. This thread made the idea pop back into my head and I'm glad to see that Jason knew about it too. Coincidentally, TED.com just posted Shai Agassi's talk on Project Better place for us all to enjoy.
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"I owe much; I have nothing; the rest I leave to the poor."
~~ François Rabelais