Streetsblog (a NYC-centric blog that is a leading voice for livable urban streets)

Streetsfilms (jillions of videos of livable streets issues and examples from around the world)

Streetswiki (collection of reference articles written by the Livable Streets community. It's a place to share information about Livable Streets topics and people.)

BikePortland.org (a Portland, Oregon-centric blog that is relevant to the rest of us)

League of American Bicyclists (National lobbying group for bicycling that organizes the annual Bike Summit on Capital Hill)

Alliance for Biking and Walking (National coalition of state and local bicycle and pedestrian advocacy organizations)

Walk Bike Berks (a firecracker start-up in Berks County, headed by Michele Barrett)

East Coast Greenway Alliance seeks to build a multi-use path network from Maine to Florida. You can help build the greenway locally by getting involved with the Pennsylvania Committee

New Jersey Bicycle Coalition - Currently based in Bergen County, NJ but with plans to tackle statewide issues.

Brick City Bike Collective - Newark, NJ based bicycle advocacy group with the goal of making Newark a more bike friendly city.

Tri State Transportation Campaign - non-profit organization dedicated to reducing car dependency in New Jersey, New York, and Connecticut.