That is a fantastic book, also 'ML for the working programmer' is really good [1]. I always wanted to use SML in anger, but the lack of third party libraries is a major hindrance. Today I think one is better served using OCaml, F#, or Clojure (this is not intended to be an exhaustive list) if a highly productive functional language is desired.

[1] http://www.amazon.com/ML-Working-Programmer-2nd-Edition/dp/0...