Advocacy and Transportation

• Best Workplaces for Commuters (EPA)
• Bicycle Transportation Institute
• Bike Arlington (NOVA)
• Bike Commuters
• BTA (Portland)
• C.I.C.L.E. (LA)
• Car Free DC
• Chicagoland Bicycle Federation
• Commute by Bike
• National Center for Bicycling and Walking
• National Center for Safe Routes To School
• Pedestrian and Bicycle Information Center
• Safe Routes to School National Partnership
• International Bicycle Fund (hub)
• League of American Bicyclists
• Thunderhead Alliance (hub)
• Transportation Alternatives (NYC)
• Velo Vision
• WABA (DC)

If you want to add to the list, just put it in a comment, and I'll incorporate it.