Oooh, and I just remembered - there's a product on the market called "Urine Off". It's in a black container (spray bottle) and available from vets. It's about $20 for a bottle, but it is seriously the *best* thing for getting rid of the smell. It's enzymes so destroys the smell - I seriously recommend it

Great advice nay23 - I might do that when we finally have a nursery set up.