http://en.wikipedia.org/wiki/GPS_eXchange_Format

Gratis program.

http://www.gpsbabel.org/download.html#downloading

http://www.easygps.com/

http://www.youtube.com/watch?v=dLzvg2vnUDM

Garmin GPSMAP 62 tutorials  with Jim Cyr
http://www.youtube.com/playlist?list=PL53A8AEE683C995BF

x, y and z as Points, Polyline, Blocks and 3D
Set from Front