Great book, i really need to desmistify my mind about Function Programming hahah, there is an very good article too check out:

Functional Programming For The Rest of Us
http://www.defmacro.org/ramblings/fp.html

I wouldn't exactly call it a tutorial :) I read it a while ago, and the reason I have a continued interest in boo is its compiler extensions, giving power similar to lisp's macros.

I still haven't made up my mind entirely. I use python professionally. The thing with lisp is that simple things tend to be more verbose, and you start winning big once you go high up the abstraction ladder. I'm too addicted to python's expressiveness to make the switch.

If only there was a lisp implementation for .net. Combining boo and lisp could be really interesting.