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.
There's a small glitch that happens if you talk to him from behind the counter. When you chat, he turns over and stay as it he is standing in front of the counter (see image). Because of this, you can also see his entire body and animation.