A new study is out: exercising is important, but standing -- well, standing is a big, big deal. The study was published this month in Diabetes, and it's been covered over at ABC.COM.
Bottom line: thin people putter around the house, fat people don't. Being vertical allows your body to manufacture enzymes that are important to metabolism; setting all day, and this manufacturing process shuts down.
So, putter, people. Putter.