Wheredroid FREE VERSION is a simple application to display your coordinates from the GPS receiver: latitude, longitude, heading, speed, number of satellites used and (it's its peculiarity) altitude and accuracy.
Altitude may be unavailable on some models (I tested it on Samsung Galaxy S and it works, even if it is less accurate than the one received by my tomtom).
Version 1.1.0 is qiote usable as an altimeter and a compass.
version 1.05.00 adds vertical speed meter
Version 1.07.00 adds the possibility to upload position to Ilpiola Mobile device tracker (http://m.ilpiola.it/t)