You can go to CVS and buy a prepaid credit card. You charge it up at the store, I forget how much they charge initially, maybe $10. You then have to call to activate it. Just keep in mind you have no recourse with those cards, you can't place a chargeback- at least with the CVS ones.

Btw, many CC companies will give you instant online approval and a number to use until you get the real card. I know American Express does this with their 'Blue' card, but I don't know which OP's do and don't take Amex.

-yawkaw