"What can I do?"
In the short term, you can donate: the links in the right-hand column provide reputable channels that allow you to earmark your donation specifically for Haitian earthquake relief.
In the longer term, you can express your support for a real, sustainable solution: to partner with a responsible, democratically accountable Haitian government for national reconstruction. The Haitian people are dynamic and patriotic. Let's give them a real chance to build their country and put an end to sclerotic and piecemeal efforts.
Write your government to support a Marshall Plan for Haiti here and now!