the COO of my company has the legendary black card. he can purchase a fighter jet if he wants. he can get into any restaurant even if they're booked (i know. i was at mortons with him). the black credit card is an unlimited credit line. and you can't apply for one. you have to be invited to get it. pretty much, you have be a a serious multi-millionaire uber-elite person.
i want one too, BUT i wouldn't spend a dime on it. i just want to carry it around. and it's made of pure titanium (it's pretty heavy, i got to hold it).
learn more at: http://en.wikipedia.org/wiki/Centurion_Card