Open Street Map. The free wiki world map. Ambitious project at point zero right now, so don’t expect to see much on the site. But definitely worth watching/supporting, don’t you think?
OpenStreetMap is a project aimed squarely at creating and providing free geographic data such as street maps to anyone who wants them. This is because most maps you might think of as free actually have legal or technical restrictions on their use, holding back people from all walks of life who would like to use a map for one reason or another.