This is to have a map away from wifi (in the mountain, at Grand Ma's home, etc).

http://www.youtube.com/watch?v=FwjZL616CYY

Everything is stored locally, no web is used.
- OSM tiles is the background. Layers are blended over :
- A tree of SRTM tiles (same projection/structure as OSM) is build from SRTM data (interpolated or averaged, as needed)
- A tree of tiles (same projection/structure as OSM) is build from a massive set of GPS tracks, to see frequently used aerial ways (paragliders).