This video from the World Bank Water and Sanitation Program describes how communities in rural Tanzania are reducing the spread of disease and creating local sanitation markets. Local masons are trained to make slabs, or Sanplats, which are more hygienic. These are purchased by households for $5 and added to existing pit latrines.
WSP (2010): Moving up the Sanitation Ladder. Marketing Latrine Upgrades in Rural Tanzania. Water and Sanitation Program (WSP) URL [Accessed: 23.10.2012]