already done: http://topomaps.dyndns.org/

drawbacks:only some regions, elevation in feet

topo data

http://srtm.csi.cgiar.org/SELECTION/inputCoord.asp

http://surfit.sourceforge.net/

does not compile on my computer (perhaps dur to 64bit?). Was thinking of using marble, the KDE google earth replacement, for extracting the elevations…

map data

www.openstreetmap.org

http://wiki.openstreetmap.org/index.php/Planet.osm

http://download.geofabrik.de/osm/

combining map and topo, creating garmin map

http://www.parabola.me.uk/mkgmap/index.html