programming in Ruby

I've been hearing so much about Ruby, I finally went out and bought a book. It's called Learning Ruby by Michael Fitzgerald. I found the book pretty good at laying out the jist of Ruby. The most interesting thing about it is that everything is an object. Even numbers are classes! This takes object orientation to its logical conclusion.
I also like the "dynamic typing" wherein the system determines the data type of a variable. While I wonder if this leads to casting problems, it is nice to have someone else take care of the details.
Will post on a Ruby podcast next.