If you do nothing else, read about each one and keep them in mind when your circumstances might make it possible to get involved later.
Use Solar, Save Lives - provides solar lamps for villages in Kenya so that there is light once the sun goes down.
Charity Water - a non-profit organization bringing clean and safe drinking water to people in developing nations. 100% of public donations directly fund water projects.
Kiva - Micro Loans around the world to provide careers for those in poverty circumstances
Give A Goat - Gifts of livestock to provide food and income.
Shelter Box - Provides housing and equipment in areas of crisis such as Haiti, China, and Sumatra earthquakes.
Andre Sobel River of Life Foundation - Help for families dealing with the crisis of a child's illness