Transportation Energy Data Book
I wish I had run across this data earlier. The Transportation Energy Data Book put together by the U.S. DOE contains tables galore, in easy to convert Excel format.
In particular, check out Chapter 8:
Table 8.16 Bicycle Sales, 1981-2002
Table 8.17 Specialty Bicycle Sales by year, 2000-2002
Figure 8.3 Walk and Bike Trips by Trip Purpose, 2001 NHTS
Also, talking about an elaborately rationalized bicycling initiative, note this Portland, Oregon group's purpose:
... riders go out to organic farms, native american communities and sustainable businesses, doing service projects and learning about sustainability.More information at the Sustainable Energy in Motion Bike blog.