The_Beaver wrote on Oct 30^th, 2007 at 10:59pm:

The movie (Sean Penn) unfortunately takes significant artistic license with the story. It portrays McCandless as more of a spiritual soul rather than a lost soul...and they created a domestic issue that is pure fiction.

That's why I won't see the movie :(
I think Sean Penn is a great actor but after his little self promoting stunt in New Orleans and hearing him on a few talk shows "romanticizing" and injecting his own personal politics into the story along with taking a far more slanted view than the author, I'd sooner reread the book ;)