Dec 18 2008
OpenStreetMap - Create and Provide Free Geographic Data to Everyone
OpenStreetMap is a free editable map of the whole world. It allows you to view, edit and use geographical data in a collaborative way.
The maps are created using data from portable GPS devices, aerial photography and other free sources. Both rendered images and the vector dataset are available for download under a Creative Commons Attribution-ShareAlike 2.0 licence.

OpenStreetMap - Create and Provide Free Geographic Data to Everyone
The availability of aerial photography and other data sources from commercial and government sources has greatly increased the speed of this work and has allowed land-use data to be collected more accurately.
OpenStreetMap is inspired by sites such as Wikipedia — the map display features a prominent ‘Edit’ tab and a full revision history is maintained.
With this great site, you’ll be able to see a user-generated map of almost every city in the world. Many users keep diaries on the site. These deal with the travels they’re taking which allow them to complete these maps. It’s very interesting to see to what lengths some people go to provide this site with accurate data.
If you have a GPS device, you will know that the maps of your home town are probably not too accurate. Even you can collaborate with pretty simple steps - Let your GPS device track your way to work, export the data as GPX, and upload on openstreetmap.org. Then go into the editor and start adding as much detail as you can.
visit website - http://www.openstreetmap.org/


