I read the book a few years ago. It's a good read and Karakauer also explores his own urge to do things most people find stupid and life threatning. His recollections of his own solo climb of the Devils Thumb and the solo glacier approach is a nerve wrecking account.
He also ask, why was it that some people came down so hard on McCandless adventure, and even thought he got what he deserved, when most peoples lifes are full of boring, yet dangerous stuff? It's certainly a thin line sometimes, but the main point I think Krakauer brought home in the book was that this guy wasn't stupid or clueless. Maybe pushing his luck, but a lot of people do that behind the wheel every day... risking other peoples lifes at the same time. That really calls for some harsh comments.
The film was good, but not fantastic. I really had a hard time with the scene where he is bucket showering in slow motion with the alaskan mountain range as a backdrop... Looked like a hair product comercial.
cheers Porphy