I have not been able to get through to the State Department's Haiti Information Number. (1-888-407-4747.) Nor was I able to get through to any of these numbers at the US Embassy’s Consular Task Force in Port-au-Prince: 509-2229-8942, 509-2229-8089, 509-2229-8322 or 509-2229-8672. You may be able to if you keep trying.
I was, however, able to reach Karen Rodriguez, the State Department's Haiti desk officer. (1-202-647-4728.) US citizens who are trying to find their relatives in Haiti, she said, and who can't get through on those numbers, should send relevant information to ACSPaP@state.gov and firstname.lastname@example.org. She said not to send photos of your relatives, but to send your contact information and let them know that you can send photos if needed.
I reached my brother in PaP by calling over and over and over again. Keep trying. Lines can open up. Apparently they can also get scrambled, so don't be excessively alarmed if you call and someone who isn't your relative answers.
Don't call any of these numbers, or Haiti, for any reason other than to try to verify that your relatives are alive and give rescuers information about their location. Don't jam up the phone lines more than they already are.