Learning Scala

Here are some places to learn Scala.

: The definitive book on Scala, by the creators of the language. Covers all aspects of the language thoroughly, in an easy-to-read way. Highly recommended given the general lack of good Scala learning resources on the Web.
A Tour of Scala: From the official Scala web site, one of the more useful guides to the Scala programming language.
The busy Java developer's guide to Scala: Functional programming for the object oriented: Ted Neward introduction to and overview of Scala

Which of these features of Scala is most important to you?