Good news for mathematicians who love watching throngs of cyclists stream by: Portland, Oregon just became the first U.S. city to install a bicycle counter!
You'll find the digital "bicycling barometer" on the AM inbound side of the Hawthorne Bridge. It was made possible by the non-profit group Cycle Oregon which purchased the machine with a $20,000 grant. Lots of yummy extra details are over at Bike Portland, including an in-depth look at how the system works.
Seattle is reportedly just about to install one as well. Which city/location in the U.S. should be next? Where would you put one in New York City?