I carry a handheld Garmin E-trex High sensitivity. I have no complaints with it other than it can suck up AA batterys pretty fast. It always gets good reception in the trees. Bought it at REI, it was pretty cheep.
For me it has three uses:
1) Just to play with
2) It has altitude info which can be interesting to compare the snowline level and just general height.
3) Most importantly to be able to call out Latitude, Longitude info to emergency response persons if someone gets seriously hurt on the trails.