After a long time I have added new feature to the grails tutorials.
The new section is favorites.
Now when you find interesting article on the grails tutorials you can add this article into your favorites. Later on you can access favorites and browse articles. Further on you can browse favorites of other users. Favorites of each user are also exposed as RSS feed so if you like somebody's collection of favorites you can follow it via RSS feed.
"Unfortunately" implementation of this feature was more or less straightforward so there is nothing I could really blog about.
More or less if you created your code with enough templates and custom tags, implementing new feature in most cases is actually adding one or more domain classes, reusing existing services and templates and using dynamic gorm methods.
Well and this is the part I really like about grails. Adding new features usually is more or less matter of hours (not days).