We always used to take out cats out on leashes, because we didn't have our fence done yet (new house), but since we have it done now, we let them roam the yard. BUT only when we are outside with them at all times. We never leave them unattended...just in case. There is a guy who lives across the alley that tempts Talon to no end...
he will sit and watch it for hours at a time! It's cute. But I still put them on their leashes occaisonally, if I need to run into the house quick and just to keep them used to the leashes.