The first project I looked at was the Kingshighway skatepark. This was a group effort by local skaters who created a skate park underneath a city highway due to the fact it had became an illegal dumping ground and because there was a lack of skate parks in general. Th only rule is you have to contribute in order to skate there which is many-to-many in my eyes because everyone who is skating there added too or created a feature which the rest use to skate on. I think it is a great idea and has put in motion to allow more of these mini skate parks to arise in the St. Louis area.
http://www.spontaneousinterventions.org/project/kingshighway-skatepark
The second project I looked at was Ghost Bikes. These are bikes that are painted white and decorated with flowers and pictures to honor bicyclists whom have been stripped of life by motorists. This idea uses the strategy of getting attention first of the community, but then all of the world due to the fact that it is such a powerful gesture. I find it amazing how it started in St. Louis, but the website GhostBikes.org is out of New York City showing just how far the movement spread.