I read the book and looked very forward to the movie coming out. While i enjoyed the movie considerably, i gotta say they scew it a bit. It's not a completely butcher job or anyhting, they do what's mostly needed for the screenplay.
One of the biggest factors i feel like they left out is the fact that .... well, let me put it this way
When i read the book. i couldn't get over how unlikable Chris McCandless seemed to be. I sorta felt like if i ever met him in person i'd be blown away by his pretense. The kinda guy that you walk away from and say to your buddies "wow, he was a dick wasn't he"
Maybe it was just me.
I don't know if it was on the radio or some late night TV show, but they were talking about how since the movie came out people have been stripping the bus. Some guy actually removed the instrument cluster and sold it on ebay.