I've been holding off making further comments about this (fantastic) book until I post some neat little things later this month, but I'll just mention one little thing to stave off those calls for more info. David Lipsky follows DFW everywhere over the five days, including to one of his Prose Classes. As a teacher myself, it was electrifying to read about his teaching style and technique.
He paces around the classroom. Happy, energetic. At one point, thinking, he even drops into a quick knee bend. Class laughs; they really like him.