In just four years, bike share has gone from being the fantasy of a few enthusiasts to a practical and low-cost way for tens of thousands of people in American cities, both large and small, to get around.
San Francisco is one of America's top bike destinations -- and Mission Bicycle is leading the charge. As the only shop in town that makes its own custom cycles, they'll help you design every component from frame size to color-coded tires.
Copenhagen has ambitions to increase the number of two-wheeled-commuters to 50% by 2015, and I hope they achieve it. Even more, I hope their progress sends a message far beyond Denmark and encourages the rest of the world to adopt pedal power, the ever-renewable-energy source.
Biking represents a simple activity and lifestyle change that could affect so many of the big, societal issues we face today, as well as some that are not given the priority they should, such as community-building and connection with nature.