If you are spending money on a gym membership and gas for your car, you're better off picking up a used bike at a thrift store for $100 or less, says Jeff Yeager, author of "The Cheapskate Next Door."
"Pedal your bike on over to your health club and cancel your gym membership (average savings: $400 per year)," Yeager says. "Then take a map and draw a circle 1 mile in radius around your house, and resolve to bicycle for all trips within that radius. More than 25 percent of all car trips made by the average American are within 1 mile of home, so you stand to save about $800 more per year on gas ... and stay in shape at the same time."