Alas, ArcGIS Explorer doesn't support Mac. Though someone around here (Bill??) recommended mapping software for the Mac. You can use a duel boot OS for Mac X (??) of course. And they're working on a runtime version of ArcGIS which should be platform independent.
Still, the basic stuff of our book -- coordinate systems; importance of GIS; and GPS are good as a basis for understanding. As a side note, I just got approval for a fully online class on GIS basics for Columbia College, Sonora, CA for next fall. I'll post details later.
but I remember being stopped dead in my tracks by Howard during a conversation about careers. I was finishing up graduate school and wondering what in the world to do with myself (but of course whatever it was would involve papers, students, and *advancement*), and he had just explained that he did Ostrander during the winter and [actually I forget what; seasonal rangering in the Valley?] during the summer. I asked him something about a "career path." He looked at me blankly (but with a twinkle in his eye) and said, "what else would I want to do?" It was much too good a question for me to be able to afford to think about at that time in my life!
I well remember sitting in the Hut in the mid-70s as HW was writing his thesis on Muir and Transcendentalism. Really terrific stuff. I'd read chapters hot off his pen and we'd talk about it. Great times. But, yep, the siren call of the mountains got him and he never finished.
"I am hopelessly and forever a mountaineer. -- Muir"
Michael Cohen's "The Pathless Way" is what he was writing about. An excellent book.