We are working on just such a beast (a full application, free,
tutorial) at http://www.buildingwebapps.com/learningrails. Our audio-
only podcast covers the high-level concepts (over 8 episodes), and we
are now switching to a screencast that will walk through iterating on
a full Rails 2.0.2 (or newer) application. BTW: this is the same
podcast found at our LearningRails.com site or iTunes, if you've
already listened to the audio portion you can jump in starting with
the screencasts.
There are a variety of show notes and the upcoming screencasts will
have code posted. We are aiming at beginners.
We hope to have the first screencast posted soon. You can subscribe to
notifications at the site.