GEB high on my list of books that I own on dead trees, but also want on Kindle. Even if it didn't qualify for Amazon's deal to get it cheaper if you already bought it from them -- even if I had to pay a lot for it.

Yeah, I know it's not an ideal format for Kindle, e.g. the illustrations and... a few other features I won't give away here. But still. What a great thing to have at-hand anytime you wanted to dive in and read part of it. Sigh.