We made a cat litter box from an IKEA drawer by sawing a door in the side and framing it with moulding. We also added a cushion on top so it's a functional piece of furniture and looks much nicer than a typical litter box.
INSPIRATION :: Cat Litter Cabinet :: How cool is this custom built cabinet? Has a built in cat door (by Pet Safe) w/ a magnetized flap along w/ a vent in the back for fresh air. Painted gray w/ black knobs & hinges. If I must ever have a cat box again.