Programming in Scala
I just noticed via Eelco's blog that the new Scala book from Artima is out:
This book is the authoritative tutorial on the Scala programming language, co-written by the language's designer, Martin Odersky. While mostly complete, the book is still a work in progress. This early access program will allow you to learn about Scala from the source and provide helpful feedback to the authors that will make the book even better.
I know what book I'm going to order for some Christmas holiday hacking...