Recommended Groovy/Grails reading?

[Leonard Axelsson]

I've met a lot of new Groovy users lately and have had a hard time
knowing what books to recommend. When I started out with Groovy it was
still "Groovy in Action" that was "the book" but today it's somewhat
outdated and a rewrite is on the way.

When it comes to Grails I think "The Definitive Guide to Grails
2ed" (isbn 1590599950) is a good read with great examples. I've got
the pdf of "Grails in Action" (isbn 1933988932) but haven't gotten
around to reading it yet myself so unsure to what it offers that the
def. guide does'nt.

Back to the question, what books about Groovy and related topics would
you recommend?

Regards,
/Leo