If you're into the occaisonal silliness in your role-playing game, try this: The next room your characters walk into is the real room in which you are all playing. Don't make it obvious at first. Start with the general size, doors, and colors. As the players explore, increase the level of detail and specificity.
If you want to take it even further, have a game prop hidden somewhere in the room in which you're playing. As the characters explore the room and, presumably, make their careful searches, describe the real location and object of the prop and see if any of your players check it out.
I got the idea for this room in reflecting over the game my grandmother and I played often. We called it "Riddely Riddely Ree", but I've heard it go by other names such as "I spy with my little eye...". The point is to hone your intuition and perspicuity to the point where you can reveal the unknown object in the room on which another player has fixated in as few guesses as possible.