Yesterday, I read about a volunteer group in Sacramento, CA area that collects used bicycles, repairs them and gives them to homeless and low income people that don't have cars. A few times each month they also set up a bike repair service in some convenient parking lot or park in Sacramento so that people with low income can get their bikes back into working order. They accept donations from the public including old bikes, bike parts and volunteers to help. They were in the paper also because they were looking for someone that would help to donate a larger trailer so that they could distribute more bikes and expand their services to a nearby city.
This was such a simple and practical idea. I was surprised that I had never heard of such a service before.