resources.rb

Merb::Router.prepare do
  identify User => [:account, :login] do
    resources :users
  end
end

# -- Generating --

url(:user, @user) # => /users/awesome-acount/my_login_name

# -- In the controller --

# -- In otherwords, #identify also sets the keys of the resource

class Users < Account
  
  def show
    params == { :account => "awesome-account", :login => "my_login_name" }
  end
  
end