Good post. The only other Socratic book I own is "What is Calculus about" by W.W. Sawyer. It's more loosely Socratic though. There are paragraphs of text interspersed with questions that either ask you to look for a pattern, or else follow a statement to its logical conclusion.

Not as good as The Little Schemer, but it's still cool that you can learn traditional (non-lambda) calc knowing only addition and subtraction.