If you have pets, I'm sure you've had an accident on the carpet situation before. We do, so we tested cleaning dog pee with vinegar to see if it works.
Real Natural Living
Condo Blues: How to Clean Dog Pee from Carpet WITHOUT a Carpet Cleaning Machine
Dogs I Want!
How to Clean Dog Pee Off of Hardwood Floors | eHow
How to Clean Dog Pee Off of Hardwood Floors | eHow.com