<p>GWT seems like a really nice technology for Java developers who don't like (or don't know) HTML/JS/CSS to build rich web interfaces. On the server-side Grails also looks really nice, it's often described as "Rails for Java developers". I've read that Grails' "convention over configuration" approach, together with the benefits of dynamic languages (Groovy) can really reduce the amount of (boilerplate) code that needs to be written, while still leveraging best-of-breed Java technologies such as Spring and Hibernate.</p>

<p>Anyway, I haven't read much about how well these technologies play together. How easy is it to integrate GWT with Grails on the server-side? I'd be interested to learn about experiences of anyone that has build an application with these technologies? Recommendations on resources (books/websites) for building a GWT-Grails website would also be very welcome.</p>

<p>Cheers,
Don</p>

with the benefits of dynamic languages
  (Groovy) can really reduce the amount
  of (boilerplate) code that needs to be
  written
That's what folks from RoR camp was preaching all the time. After some initial boom RoR projects got into inevitable trouble with bigger projects. The bigger projects the more work one should delegate to compiler, i.e. the more valuable are static languages. Currently, RoR boom is all but gone.
The amount of (extra) code you need to write now with JPA/Hibernate, for instance, is almost zero. Annotations only. It even finds the mapped beans itself, in runtime, via classpath! SpringFramework makes many other "boilerplate" codepieces obsolete too.
In my GWT project (one so far, have to admit) I use JPA (Hibernate), DAO layer, business delegate pattern and it's easy and robust.