If you still haven't chipped in any money to help with the recovery efforts in Haiti, I've got two suggestions for your tax-deductible funds:
1. Partners In Health, which has operated medical clinics throughout Haiti, primarily in more rural areas outside of Port-au-Prince. Because of this, PIH already has hundreds of doctors and nurses in Haiti that will be setting up a field hospital in Port-au-Prince and treating patients at their primary facilities. You can donate money specifically for earthquake relief over at their site.
2. Doctors Without Borders probably doesn't need an introduction.