Topic: HOWTO: Tutorial and Example App for Rails 3 with Mongoid and OmniAuth
I've put together an example application that shows Mongoid and OmniAuth working together on Rails 3. Mongoid is for data storage (alternative to SQL databases). OmniAuth is for OAuth authentication using Twitter, Facebook, LinkedIn, GitHub, and many other providers.
It's on GitHub:
Tutorial for Rails 3 + Mongoid + Omniauth by Daniel Kehoe
Example app using Rails 3 + Mongoid + Omniauth by Daniel Kehoe
There are options to use RSpec, Cucumber, jQuery, Haml, and Heroku as well.