Immediately after the earthquake, the main source of information was Twitter, which I have a new respect for. Journalists and aid workers are arriving in Haiti and we are gaining a better sense of just how extensive the damage to Port au Prince is. We also know that Jacmel was seriously affected as well. Aid from the United States, other governments, and humanitarian responders both big and small is picking up. This is a summary of the current situation, who is doing what where, and how you can help. Additional updates will be posted as comments.