##Routes.rb:
  map.resources :workshops,
    :has_many => [:assignments, :message_boards, :chat_rooms, :workshop_profiles, :my_works, :my_desks, :emails , :users ]

  map.resources :users
    :member     => { :email   => :get }

  map.resources :emails,
    :collection => { :email_workshop => :get, :send_email => :post },
    :member     => { :email_user     => :get }

## Kind of URL I want to generate:
/workshops/45/email_workshop
/workshops/45/email_user/99

## Although I can live with (or something similar):
/workshops/45/emails/email_workshop/45
/workshops/45/emails/email_user/99

## Inside my emails controller:
def email_user
  user = User.find ...
end

def email_workshop
  workshop = Workshop.find ...
end