Some feaures from Rails 2.3 that I wanted to highlight:
rails app -m mytemplate or a template can even be applied to an existing project. Browsing templates on GitHub is also a nice way to see which tools and techniques other developers are using.
Nested Model Forms
It is complicated but it saves code.
Use Seed Data
Managing seed data in the conventional rails way makes it easier for new team members to figure out how to get development data to work with.
rake db:seed and
rake db:setup are new tasks to manage application data while the application code is being developed.