gistfile1.rb

class Users::Register

  def self.call(attributes)
    new(attributes).call
  end

  def initialize(attributes)
    @attributes = attributes
  end

  def call
    if valid?
      save_user
      create_empty_profile
      notify_admins
    end
  end

  private

  def valid?
    user.valid?
  end

  def user
    @user ||= User.new(@attributes)
  end

  # etc...

end


# Later on, in the controller for instance:

Users::Register.(params[:user])

Cool technique.