Minimalist IKEA Cabinet Hack, and lots of other ideas on hiding a litter box. Not just for the litter box but for a dog's or cat's pet bed, when company is over or just during the day, just shut the door and it won't have to be seen until bedtime.
Cats Toys Ideas - I like the idea of making a ramp to encourage the use of their back claws. We may have to make it a little lower for our cats, but it still seems like a great way to encourage exercise. - Ideal toys for small cats