Have no fear. Swallowing gum won't muck up your insides. It passes through the digestive system just like everything else you eat. It's digested like celery and other roughage, which is pretty much not at all. Still, it makes its way through and won't stick around any longer than normal. Gum can be a choking hazard, however, so keep it away from kids five and under.

Don't worry about your knuckles either. Cracking them won't damage your joints. Here's what happens when you hear that crack, snap, and pop: Each joint is lubricated by a gummy substance that absorbs air and creates a vacuum. When you pull, the seal breaks and gas bubbles pop. In 20 minutes, the vacuum re-seals.

One more: Drinking coffee. Is it a vice? Nope. Unless you are pregnant, there's almost never a health reason for adults to give up their coffee habits. Some studies show that drinking coffee can better your health -- one study of a bunch of nurses suggests two cups of coffee per day lowers the risk of women developing diabetes.

Got a "bad" habit you suspect isn't all that bad? Tell us what it is and we'll investigate.

Source: Better Homes and Gardens, April 2008