From the Onion, here are some tips on how to be a good house guest:

• Always help your hosts after dinner: Offer to clear the table, wash the dishes, or teach them to cook.
• Ensure that you do not overstay your welcome by asking your host if you are overstaying your welcome every couple of minutes.
• Avoid an awkward moment later on by telling your host upfront that you're a bedshitter.
• Playing your host's stereo at top volume after midnight is rude. Bring your own boombox.
• Don't just act like a guest in someone's house. Be a guest in someone's house. 
• It's considered good form to replace any cats you drown.
• Cooking a meal for your host is a nice gesture, but ordering a pizza and offering to chip in for your part is way easier.
• Should an unfamiliar household situation arise, do not speak. Stare blankly at a fixed point on the wall until it all blows over.
• Don't monopolize the bathroom: Take sponge baths in the kitchen sink, and pee in a bottle and hide it under the bed.
• It's customary to take a souvenir from your host's home as a reminder of your wonderful stay.