Unless they're getting a deal on their payment processing for being a charity, I'd suggest taking the extra minute to go to their website.  Credit card payments will cost them less than fifty cents of that $10.  Cell phone providers charge <i>much</i> more.<p>Also, while charities love to use current events to drive fundraising appeals, their current disaster is almost universally paid for by funds they collected months ago.  If you're going to give, give smart.  (Relatedly, this is why sending non-monetary goods after a major disaster is perhaps less effective than you might wish it would be.)