In 90 minutes, Garg, Matt and David built a working web photo sharing web site. Garg played customer. David played whip-cracker (um... PM), and David did all the heavy lifting with Rails.
This talk was a high level introduction to the speed and power of Rails as a development environment. As such, I found most of the material repetitious of other demos I've seen. But, the guys did a good job of showing off the Rails notion of "convention over configuration." They also showed off RSpec and demonstrated the plug-in architecture.
Recommended resources (from Garg, Matt and David):
I would have liked the session to be more hands-on. I'll have to check out the Rails lab for that level of immersion.