I'm pretty sure Disney will take a credit card for as many points as you want as long as you have enough balance remaining on the card. (Not positive, though.)
As far as I know, you usually can't use credit cards for real estate. I was just told by one reseller that they would be able to accept the checks that credit card companies tie to the card, but not just the card itself. For my credit card company there is a significant cost associated with the checks, so we're just going to use a regular old check. Bummer - no FF miles for us!