Smallpox was declared eradicated in 1980, making it the first infectious disease to be wiped off the face of the planet. This is an amazing accomplishment for humanity, and deserves an appearance on the silver screen - anyone want to write the script? Start by talking to D.A. Henderson.
An equally dramatic but under-reported story is the impending eradication of Guinea worm, a parasitic disease directly related to unsafe drinking water and inadequate sanitation. The Guinea worm is a particularly unpleasant critter, with a nine month+ lifecycle that makes it difficult to control much less eradicate.
Eradication protocol differs from that of smallpox in that eradicating Guinea worm relies not on a vaccine but on simple, life-saving water and sanitation infrastructure and hygiene promotion activities: drilling boreholes, purifying surface water, and teaching people (primarily villagers in rural communities in nine African countries) not to enter bodies of water when they are infectious.
The Carter Center and others expect to completely eradicate this parasite by 2009. Succeeding in this will be a testament not to the Carter Center's good works per se but to the ability of the poorest communities in the world to solve their own public health challenges with minimum inputs from the international donor community. It will be a testament to the importance of basic water and sanitation as a foundation for overcoming all public health-related challenges and meeting the Millennium Development Goals. Its success will also give the polio eradication initiative of Rotary International a nice kick in the pants.