[xhippee]

The answer is quite simple...for us.
We keep the litter box in the 'laundry room' just inside the garage door leading to the house. It's a covered box, and with an air freshener sitting on top, no one ever knows it's there.
Of course we keep it kleen, because if I ever get a whiff of cat do-do, the cat's history. Nothing like going into someone's home, and instantly you think you're in a Ken-L.
Last bit of advice: starve the kitty.