Another tidbit I came across at RailsConf is Hobo. I haven't tried it myself but did just go through the screencast and tutorial. I think it's worth a closer look.
"Hobo is a plugin for Ruby on Rails that brings a number of extensions—some small some large—to Rails application development. The common theme to these extensions is rapid development.
Like Rails itself, Hobo encapsulates a number of opinions about web application development. The opinion that is most central to Hobo is this: we have found that there is a great deal of similarity from one web application to the next. Much more similarity in fact, than is supported by today’s frameworks. We would rather implement this stuff once." (from Hobo Web Site)
The question with these kinds of packages is whether they are flexible in the right ways or whether they will get in your way when you try to do what you need to do. I can't answer for sure.
If you are looking for a further accelerator for building Rails apps, Hobo is a good option to explore.