Another option: I have a Suunto watch that provides altitude (which I use), and barometric pressure and a compass (which I don't use), besides the normal watch functions.

It's pretty cool for skiing or bike climbing, if you do repeated runs. It'll keep track of how many runs you've done AND the cumulative vertical meters. I set it when I start the day on the ski slopes, and can see exactly how many runs and vertical feet I did when I finish.

I've used it to figure out the elevations and climbs I do on all my "regular" training routes.