The NYTimes has a story on the VÃ©lib bicycles newly available for rent in Paris. The pricing system seems especially appropriate for bicycle commuters: free for the first half-hour, 1 euro for the second half-hour, 2 euros for the third half-hour and 4 euros for each half hour after that. Many factors would need to work together to make such a system work in the US, including size of the city (populous enough to support a regular ridership, but not so sprawly as to make short bike trips impractical), number and location of stations, and biking infrastructure, to name a few. NYC comes to mind as a place where the US version of the VÃ©lib could take root. Modify the gear ratios, beef up the brakes and San Francisco might be in the running. Making the bikes tourist friendly may be a necessity, but it could also open up possibilities for cities like DC or Charleston, SC or numerous national parks.