My dad was active in helping out in the formation of this charity, and it's blossomed into one of the best ones on the ground in Pakistan. Plus you can pay with paypal or credit card, which is a MAJOR plus. I've decided on giving my aid to this one, and recommend it highly. I still know some of the people high up in it, and they do FANTASTIC work both in and outside disasters.
http://www.thecitizensfoundation.org/floodrelief.html