In hotels, a concierge assists guests with various tasks like making restaurant reservations, arranging for spa services, recommending night life hot spots, booking transportation (limousines, airplanes, boats, etc.), procurement of tickets to special events and assisting with various travel arrangements and tours of local attractions. In upscale establishments, a concierge is often expected to "achieve the impossible", dealing with any request a guest may have, no matter how strange, relying on an extensive list of contacts with local merchants and service providers.
http://en.wikipedia.org/wiki/Concierge