Banshee was mewling like crazy at the window when we were outside, so this weekend we got her a harness and leash. She very much enjoyed getting to explore the yard, plus it got her some bonus diaper-free time!
We tried this with the older two cats a long time ago, but they did *not* like it. One just squatted in place, the other tried to climb my head! A leash would not be a good idea for Phantom, Banshee's "brother", since he's a troublemaker and would probably get stuck in a tree or something.