■

gem install devise

script/generate devise User

app/models/user.rb

class User < ActiveRecord::Base
  # Include default devise modules. Others available are:
  # :http_authenticatable, :token_authenticatable, :confirmable, :lockable, :timeoutable and :activatable
  devise :registerable, :database_authenticatable, :recoverable,
         :recoverable, :rememberable, :trackable, :validatable

  # Setup accessible (or protected) attributes for your model
  attr_accessible :email, :password, :password_confirmation
end

db/migrate/20100712034250_devise_create_users.rb

class DeviseCreateUsers < ActiveRecord::Migration
  def self.up
    create_table(:users) do |t|
      t.database_authenticatable :null => false
      #t.confirmable
      t.recoverable
      t.rememberable
      t.trackable
      # t.lockable

      t.timestamps
    end

    add_index :users, :email,                :unique => true
    #add_index :users, :confirmation_token,   :unique => true
    add_index :users, :reset_password_token, :unique => true
    # add_index :users, :unlock_token,         :unique => true
  end

  def self.down
    drop_table :users
  end
end