I raised the flag of Haiti outside of my store in sympathy with the victims of the earthquake. The flag is available for free for anyone wanting to show that they care.
I also strongly ask you to consider a donation to whatever aid organization you know and trust - mine has just gone to the Norwegian Red Cross. They are currently shipping a field hospital to Port-au-Prince. Also, there are various in-world efforts going on, Jeska Linden has summarized these in her post.
I visited the cathedral in Darkwood mentioned in Jeskas post; it has a nice corner where you can lit a candle and have a moment of peace. My RL is rather hectic at the moment, so I kind of needed that!