Capital One has a Miles One card that purportedly allows you to earn miles for any airline. However, the offer is really that you can earn TRAVEL on any airline. 18k 'miles' gets you a ticket in the same time-zone. 25k 'miles' gets you a coach ticket in CONUS. No black-out dates or seat restrictions.
Visa's Signature card product and MasterCard's World MasterCard have similar FF benefits. They aren't giving miles in FF programs, just accumulating points to be redeemed for travel.
Cheers,
'toad