Religious ZAKA volunteers worked through Shabbat to save victims of the Haiti earthquake and managed to save 8 students from a collapsed building.
The IDF arrived in Haiti and managed to save one man after four days in the rubble:
So far, I have seen the following countries give aid to Haiti:
The United States, Canada, Ireland, Britain, France, Spain, Iceland, the Netherlands, Belgium, Sweden, Luxembourg, Israel, Italy, the EU, China, Denmark, Venezuela, Germany, Mexico, Taiwan, and Cuba. Other reports include Belize, Brazil, Guiana, Japan, Morocco, Russia and Chile.
The only Arab country in that list is Morocco. The oil-rich Gulf states are certainly following the news from Haiti but their newspapers don't go beyond that with any news that I could find about offers to help.
CORRECTION: The YNet article I linked to did mention some people in Haiti from Jordan, Qatar and Egypt. (h/t Womble)
Al-Arabiya details tons of aid en route from Kuwait, Qatar, Jordan, Lebanon and Iran.
The LA Times blog mentions much aid coming from Arab countries, and notes the conspicuous absence of Saudi Arabia from the list. (h/t Suzanne)
UPDATE: The birth of a baby in Haiti named Israel: (h/t Suzanne again)