Mountaintop radio operating is one my favorite ham radio activities. In particular, there is a 9000 foot mountain within a short drive/hike from my house called Mt Herman. It is a great hike in the summer to get a little exercise and some great views. Lately, I have also been hiking or snowshoeing up there in the winter for the ARRL January VHF Sweepstakes. See my blog posting on the 2007 January expedition.