Groovy and Grails

Since I'm interested in increasing my RAD repertoire, I've decided to spend some of my research time on Groovy and the associated Grails web app framework, in addition to Scala. One nice thing about Groovy for an experienced Java developer is that its syntax is closer to Java than Scala's, while still running on the JVM and integrating nicely with Java. While familiar syntax isn't everything, it definitely can make your first steps into a new language a little easier. Grails follows a similar philosophy to that of Ruby on Rails, a well-known "coding by convention" web app framework, but integrates with established Java technologies like Spring and Hibernate. I wish they hadn't chosen a knock-off name like that, but it still looks pretty interesting. In order to learn Groovy, I decided to buy the book Groovy in Action, after seeing a lot of positive reviews for it on Amazon. I'm also checking out various articles I can find online, including the following:

• Jeff Brown on Groovy for Java Developers
• Mastering Grails: Build your first Grails application
• Grails Framework Reference Documentation
• Graeme Rocher on the Grails Plugin Architecture
• IBM DeveloperWorks Series: Practically Groovy
• Groovy Zone (at Developer Zone)
• About Groovy

Any other suggestions for me?