Today is National Bike to Work day.  It was started back in 1956 by the League of American Bicyclists and has steadily grown into a major event.  In some cities like San Francisco, thousands of people participate every year, and many are supported by corporate sponsors.  Another West Coast city has adopted Bike to Work Day in a big way.  Portland, Oregon ranks first in the percentage of people who ride a bike to work on a regular basis.