./script/generate oauth_provider 

This creates an OAuth Provider controller as well as the requisite models.

It requires an authentication framework such as acts_as_authenticated, restful_authentication or restful_open_id_authentication.

If you generated the migration file (true by default), make sure you run
rake db:migrate

You need to add the following routes to your config/routes.rb file:

map.resources :oauth_clients
map.oauth '/oauth',:controller=>'oauth',:action=>'index'
map.authorize '/oauth/authorize',:controller=>'oauth',:action=>'authorize'
map.request_token '/oauth/request_token',:controller=>'oauth',:action=>'request_token'
map.access_token '/oauth/access_token',:controller=>'oauth',:action=>'access_token'
map.test_request '/oauth/test_request',:controller=>'oauth',:action=>'test_request'

include the following in your user.rb

has_many :client_applications
has_many :tokens, :class_name=>"OauthToken",:order=>"authorized_at desc",:include=>[:client_application]