Henry, a Harness, and Happiness All in One

When I adopted Henry in 1999 I made the decision to only let him out under my supervision because I feared that if he went out on his own he would either get lost, stolen, attacked, or killed so the only sensible solution was to outfit him in a harness while I watch him tiptoe through the grass,

 munch on grass,

sneak up on squirrels, 

wander through the bushes, 

and feel the sun on his face!

How many cat owners allow their cats to roam outdoors unattended? With a harness? A little of both? Or are indoor only cats?