We have a very active bike rack at work so I feel pretty confident leaving my bike there during the day. I do use a kryptonite U-lock though.

At home I keep in the dining room propped up against the wall. I'll move it to the back patio, or into the den (hardwood floors) to do repairs or tinkering.

I also carry a kevlar/steel keyed cable lock in my backpack at all times for quick trips to the store and such. If I had panniers I would probably just take the u-lock with me, but it's really freakin' heavy and I'm afraid it will bash up my laptop. So the u-lock stays at the bike rack.

Come to think of it, is this common for anyone else? Do a lot of other folks have people leaving big bulky security devices at the bike racks at work/school? It honestly didn't even occur to me until one of my co-workers mentioned it.