OpenStreetMap is a wiki map of the world created by the public. Started in August 2004 in England, OSM has spread around the world and as of writing has over 50,000 users with 5,000 or more contributing per month. Contributors use GPS devices to 'trace' roads and other features whilst recording details such as street names, locations of post boxes and so on. These are then uploaded to openstreetmap.org to create a map of the world. Traditional maps typically have restrictions on them such as copyright and use-case contract restrictions (say, no use on mobile phones). OSM aims to be Free, Open and Global