OpenSkiMap
From OpenStreetMap Wiki
A new project started by Russell Porter in early 2011 for providing better editing tools and renderings for winter snow sports users.
The project is integrated into Skimap.org.
Editing/rendering functionality can be accessed by visiting the relevant ski area page, which will have an OpenSkiMaps section at the bottom, listing rendered OpenStreetMaps, and access to the Potlatch 2 customized editor.
Currently available:
Customized Potlatch 2 editor
KML Ski Map Rendering
Coming Soon:
Tiled Rendering
GPS Rendering
More!