Believe it or not, these cards help whittle your balance. By Joan Goldwasser, Senior Reporter January 3, 2011 Debt-ridden American consumers are reforming their free-spending ways. We've paid off $160 billion of revolving debt (almost all credit-card debt) since September 2008. It may seem counterintuitive, but some credit cards actually encourage this new frugal behavior. The cards below are all good deals -- at least for the first year. Discover's no-fee Motiva card rewards cardholders who carry a balance for making monthly payments on time. Do that six times in a row and you receive the next month's interest as a Pay-On-Time Bonus. You'll receive your interest rebate twice a year if you pay on time every month. And you earn up to a 1% cash-back bonus on purchases. Automatic payment reminders and free payments by phone help cardholders stay on schedule. Citi Forward card users who pay on time for three months in a row and stay under their credit limit receive a reduction in their interest rate of 0.25 percentage point (you can earn a maximum reduction of two points). Holders of this no-fee card earn ThankYou reward points for every dollar they spend, and they earn additional points for paying on time. Points can be redeemed for cash, travel or merchandise. Use the no-fee Capital One MTV Visa card and you'll earn 25 bonus points each billing period that you pay on time. You also earn five points for every dollar spent on entertainment, two for money spent at restaurants and one for all other outlays. Redeem the points for MTV merchandise or for shows, cash, airline tickets or gift cards. Or you can donate your points to charity.