- Soles4Souls is a shoe charity that gives "gently used" shoes to those in need. The Soles4Souls team coordinated relief efforts for the Asian tsunami and Hurricanes Katrina and Rita, netting over 1 million pairs donated for these disasters.
- Nike's Reuse-a-Shoe program collects worn-out athletic shoes (any brand, not just Nike) and recycles them (rather than going into landfills) into material used in sports surfaces like basketball courts, tennis courts, athletic fields, running tracks and playgrounds for kids around the world.
- One World Running is an international program promoting an awareness of health, fitness and nutrition by providing running shoes to those in need in the United States and around the world.
- Shoe Bank provides shoes for 20,000 people every year -- primarily children, both in the United States and abroad.
- Share Your Sole is an Illinois-based organization that collects, cleans, and distributes gently-used shoes to needy and impoverished people all over the world.
- Shoe4Africa is a nonprofit organization that distributes gently used running shoes to those in need and also initiates HIV/AIDS awareness programs.
If you know of other organizations collecting used running shoes, please email me about them.