Cindy Medure only uses credit cards that give her cash back when she buys something.

"If a card doesn't have rewards," she said, "I cancel it."

Now that gasoline prices are reaching record highs, the Columbus resident is shopping around for a credit card that will give her more cash back when she buys gas for her sunflower-yellow Volkswagen New Beetle.

She's in luck. A handful of credit-card companies are beefing up their gas-related incentives in a bid to lure customers concerned about high prices.

"Gas-reward cards are the hot thing right now," said Brad Stroh, founder of Bills.com, a consumer-finance Web site based in Sacramento, Calif.

Discover recently unveiled a driving-themed credit card offering up to 5 percent cash back on gasoline purchases and car repairs. Chase, American Express and Citibank are offering up to a 6 percent rebate on gasoline purchases at just about any filling station.

Credit-card companies are good at identifying "consumers' current pain point and matching it with a rewards program," Stroh said. "When it costs $50 to fill up your tank and you see an offer to lower that cost, it's hard to resist."

About 34 percent of consumers have a credit card that offers some sort of gasoline rebate, according to CardRatings.com, a nonprofit consumer group. Of those, 79 percent said they plan to use their card more often to help offset high prices at the pump.

Central Ohio drivers paid an average $3.24 per gallon for regular unleaded Friday, according to ColumbusGasPrices.com. That's about 43 cents more a gallon than this time last year and 28 cents more than one month ago.

About 50 percent of credit cards offer some sort of reward program, according to Boston-based research firm Celent. The group estimates rewards cards will account for 90 percent of all credit cards by 2010.

They're popular because the lure of free stuff and cash rebates is just too great for people to resist.

"If I can get a great TV or an airline ticket, why wouldn't I put the money I spend every day on the card," said Gayle Bock, director of card-portfolio management for Merrill Lynch. "Years ago we wouldn't have dreamed of charging our groceries or our gasoline. Rewards cards changed that."

Rewards cards, including those with gas rebates, "are a good deal for a lot of people who are responsible with credit," said Lynnette Khalfani, author of Zero Debt: The Ultimate Guide to Financial Freedom.

"Unfortunately, the vast majority of people are not responsible with their credit cards."

"You can rack up great benefits," but if you carry a balance, the amount you pay in interest or fees can cost a lot more than what you are saving on gasoline.

If you aren't among the approximately 40 percent of Americans who pay their cards off every month, you should be looking for the card with the lowest fees and the lowest interest rate, not the best rewards, Stroh said.

Rewards cards sometimes have "above-average fees and interest rates," he said.

Some use double-cycle billing, a controversial practice where consumers are charged interest on the credit card's average daily balance over two months instead of one. It usually results in finance charges at least 50 percent higher than those calculated using a single month's balance, according to the Government Accountability Office.

Also be aware that you may be tempted to spend more when purchases are offset with a future reward.

Still, demand for perks, especially gasoline rebates, is high.

When Chase issued its "Freedom" Visa in September, it was one of the most successful credit-card launches in the company's history, said Donna Barrett, retail segment director for Chase. The card offers up to a 3 percent rebate on gasoline.

Discover's "Open Road" gasoline-reward card, which was released in April, has been very popular and has drawn new business to the company, said Julie Loeger, vice president of rewards marketing for Discover Financial Services.

Credit-card issuers see this demand as an opportunity to gain new business and give something back to longtime customers.

And the demand for gasoline rebates probably isn't expected to die as long as gas prices stay up.

"Everybody has to buy gas," Barrett said.•