One month after the Denver debut of B-cycle, the first large-scale bike sharing program in the U.S., over 3,000 Denver residents have burned over 1.3 million calories by pedaling away at the 400 bikes docked at 42 stations around the city. That’s according to Amadeus

Consulting, the Boulder, Colorado neighbor of B-cycle creators Crispin Porter + Bogusky who develop the integrated technology for the system that tracks usage through a kiosk user interface, Web services, and an iPhone application.

The iPhone app, which launched last week, has had about 600 downloads out of a total of just over 3,000 members (users have to pay a membership fee ranging from $5 for 24-hour use to $65 annual passes, on top of hourly rental fees to be able to borrow the bikes). The app can be used to locate and unlock bikes around the city and monitors time, mileage, and calories burned based on trip distance. It also reports the reduction in

carbon emissions achieved by biking rather than driving and allows

members to connect with each other through Facebook and Twitter. Users can go on the B-cycle Web site at any time to monitor their accounts in more detail.

The technology also helps Denver Bike Sharing, a nonprofit that manages the service, to make sure bikes are readily available throughout the city. According to a DBS spokesperson, the perfect ratio of bikes to spaces is 2/3 full to 1/3 empty. DBS monitors the ratios throughout the day, but should those numbers become too uneven, the team employs a radically low-tech solution: They deploy riders to go and shuffle the bikes. And even though B-cycle bikes have a built-in honesty policy–they’ll charge your account a whopping $1,000 if it doesn’t get returned within three days–the bikes are also equipped with trackable RFID tags which act like GPSes to prevent theft.