[Tutor] Suggestions for a good book on functional programming

[Karthik Gurumurthy]

Since i started python, i have been fascinated by this feature. Now i find
Java very boring.
I have found some of the discussions in tutor to to be very informative.
Since most of the guys here have programmed on a pure functional
languages before, can someone suggest a good book (haskell, scheme anything
is fine)
for the same. If i have to buy one which one w'd you recommend?

Yesterday i came across a title:

Introduction to Functional Programming using Haskell
..Bird

any ideas as to whether it is good?

regards,
karthik.