Dryer,

If I were to use an altimeter besides my GPS I think I'd want a parachuting wrist altimeter. I could set it to the starting altitude and then it would act like a VOR needle pointing the direction to the altitude I was supposed to be at.

As for a thumb compass, I've seen them in videos. I'm kind of headed in a different direction than orienteering courses. But I'd love to hear from Ringtail on techniques.