My friend loves Jillian Michaels! There are Jillian Michaels exercise programs on our "on demand" telelvison. I'll have to give them a try. I currently use the treadmill (which I have at my home). I don't go on it long; only a half hour a day. I also use small 5 lb. weights to shape my arms.
I totally agree that chasing the kids around, cooking and cleaning is a great form of exercise! I have two chldren myself.