Cities that bike commute
These are the top six cities in the country for percentage of commuters who travel to work by bicycle. The study by the League of American Bicyclists can be found here.
Percentage of commuters in the Washington, D.C., area who travel to work by bicycle. The PDF of the 2007/2008 Household Travel Study can be found here.
Very good use of Swivel for presenting these stats. There are a few other stats I think would be good here, such as miles of biking, etc. But, this is attractive and informative. Nicely done.