Well, Programming Language Pragmatics was too heavy (physically, that is... it's a huge hardcover textbook) for me to read on my commute, so I'll have to try to work through it at work or home.
Now my commute is being spent learning Lisp, via Paul Graham's ANSI Common Lisp. So far it's absolutely excellent. Paul Graham must be one of the most articulate voices in computing. Everything I've read by him (check out his website) has been incredibly well written: interesting, clear, concise, and generally pretty convincing. So far ANSI Common Lisp is the most readable and enjoyable programming language book I've come across, eclipsing my previous favorite: Programming Ruby. The Lisp community is lucky to have this guy as an advocate.