The Concierge (real name unknown) works on the front desk of Strangetown Hotel in The Sims 2. He is a unique character, as he is an NPC but interacts with the player's sim on a regular basis and has an impact on the main storyline.
The Concierge will ring you if someone checks out of the hotel when you're not on the game and may also ring just to tell you other information. Your sim can interact with the Concierge by chatting to him, and he will give tips on what to do, or you can check the registry to see who is currently staying in the hotel and when they're due to check out. Bills which need to be paid will also be left on the front desk.