In Capital One's TV commercials for its no-hassle-miles credit card, comedian David Spade embodies the frequent flyer's nemesis, portraying the airlines as ruthless naysayers, denying every request from customers trying to redeem their frequent-flyer miles for awards.

Airlines sidestep the limited-awards charge but point out that their programs offer a range of mileage-earning opportunities that puts the Capital One card and other bank cards to shame.

Confirming both sides' arguments, the business world's keenest minds have been working to combine the best features of airline-linked credit cards (miles for charges combinable with miles earned for flights and a host of other partner transactions) and bank cards (miles redeemable for tickets that are free of the airline programs' capacity constraints).

The search for the ideal rewards card has yielded several hybrids.

Like the Capital One card, the PremierPass card from Citibank awards points, which can be cashed in for flights on any airline without the onerous capacity controls associated with airline-specific cards.

Unlike other cards in its category, the Citibank card also awards miles for flights: Charge an air ticket for a 3,000-mile flight to the card and earn 3,000 miles, as well as one mile per dollar on the ticket's price.

But adding flight miles to miles-for-charges is only a partial fix.

The advantage of airline cards, which award miles for transactions with hundreds of retailers and service providers as well as for charges, cannot be easily matched by banks' proprietary awards programs. That suggests adding new benefits to airline cards might be a more fruitful approach.

The American Express/ Delta SkyPoints card lets cardholders have it either way. SkyPoints can be exchanged for miles in Delta's SkyMiles program and then redeemed for capacity-controlled awards. Or they can be redeemed for discounts on paid Delta flights.

While the SkyPoints card looks good on paper, an informal survey suggests that consumer response has been tepid (American Express won't divulge cardholder numbers).

That is partly a result of the SkyPoints card's being marketed alongside the traditional SkyMiles card, also issued by American Express. Two cards affiliated with the same airline, but which earn different rewards ... it's a recipe for consumer confusion.

United unveiled its solution to the problem on May 1 — significantly, the 25th anniversary of frequent-flyer programs — with the launch of its new Mileage Plus Choices Visa card, which, the airline boasts, will "reinvent" airline mileage programs. Hyperbole aside, the Choices card is a milestone in the arena of rewards cards.

Like the Delta SkyPoints card, United's Choices card rewards cardholders with a currency which is related, but not identical, to miles. On the accumulation side, Mileage Plus members earn one Choice for every dollar charged to the card.

On the award side, a Choice is like a mile insofar as it can be combined with miles earned through the extensive network of Mileage Plus partners and redeemed for free flights on United and its airline partners. But Choices surpass miles in value by offering additional awards.