20 unusual ways to save money: Exercise ball as a chair

Why spend money for a gym membership when you can work out all day long for the one-time investment of about $15? That's what you can do if you switch out your office chair for an exercise ball. You'll work your core muscles, straighten your spine, ward off back pain and have better concentration too. It's a no-lose situation,except, perhaps, for enduring the snickering of colleagues who aren't yet in on the trend.

Trend? Yes, using an exercise ball as an office chair is something of an underground phenomenon, and you can find plenty of testimonials out there on the Web, from the walking enthusiast who switched to better her cross-training, to a top 10 list of reasons to make the switch, to the class of fourth-graders who use balls as chairs. The Wall Street Journal did a long piece on the ball as chair last year, so it made it into the corporate domain -- with the biggest problem cited being "exhaustion." For those looking for a good workout, that's actually a positive!

There are gizmos you can buy to make the balls more like chairs, with stands and back rests, but the typical way to use the ball is just to pump one up and sit on it. Do you fall down? No.