The OpenStreetMap Wiki's project aims to create an altitude profile for (cycle) routes using NASA's SRTM3 altitude data. The primary focus is to import SRTM data, develop a RESTful interface, provide a demonstration website, calculate altitudes in routes, and ensure accurate performance testing. The actual platform is equipped to take inputs via XML, Google Protocol Buffers, and HTTP/GET, and output in XML, protocol buffers, and gchart.
Route altitude profiles SRTM - OpenStreetMap Wiki
http://wiki.openstreetmap.org/wiki/Route_altitude_profiles_SRTM