Historically hydroponics has been touted as a feasible way of growing foods in third world countries. Unfortunately, this has not proven to be the case. The expensive start-up cost along with electricity requirements for water circulation have proven to be extreme hindrances in poor countries. Hydroponics has been proven though to be an effective space saver and can productively grow lots of food in a small amount of space. Hydroponics simply is growing plants in a soil-less environment and giving plants the nutrition they need through exposure of the roots to water that contains fertilizer in it. Recently, a new low tech hydroponics system that overcomes these historical failures was developed in the Philippines. In its short history it has already proven itself as extremely effective and is transforming communities in the Philippines by providing a safe and inexpensive food source. It also has allowed communities to generate new streams of income by selling food grown in their system. The system is known as the Simple Nutrient Addition Program (SNAP). It uses a reservoir for the nutrient solution to sit in and a cover for the reservoir with pot sized holes in it. Plants grown in pots or small baskets are stock in the reservoir cover holes and the roots hung down into the nutrient solution. Extremely simple, easy, and inexpensive yet very effective. This is so cheap and easy that I am highly considering making my own system in the near future.
Here is a blog with some good basic information on the SNAP system: http://hydroponics-snap.blogspot.com/