If you want to help the people of Moore, Oklahoma:
The Red Cross has set up shelters in various communities. You can donate to the Red Cross Disaster Relief fund here, and the organization also suggests giving blood at your local hospital or blood bank.
If you want to send a $10 donation to the Disaster Relief fund via text message, you can do so by texting the word REDCROSS to 90999. As in the case with other donations via mobile, the donation will show up on your wireless bill, or be deducted from your balance if you have a prepaid phone. You need to be 18 or older, or have parental permission, to donate this way. (If you change your mind, text the word STOP to 90999.)
Phone: 1-800-RED CROSS (1-800-733-2767); for Spanish speakers, 1-800-257-7575; for TDD, 1-800-220-4095.
Do not send food, clothing, or toys. They just get in the way. They need cash and blood.
There are plenty of other charities and agencies to choose from as well. And, of course, there will be charlatans exploiting the emergency, so make your contribution of your own initiative and hang up on those who call you out of the blue.