NOAA's Drought Information Center http://www.drought.noaa.gov/
A collection of sites related to drought and climate conditions in the United States (and some individual states). It includes current reports, outlooks, and indices used for drought and moisture monitoring .
National Drought Mitigation Center http://drought.unl.edu
The National Drought Mitigation Center provides information to help people and institutions reduce vulnerability to drought, stressing prevention and risk management.
Monitoring and Early Warning http://www.earlywarning.nl/
Maps providing monthly updated, distributed information on rainfall, actual evapotranspiration, radiation, drought and desertification indices, and crop yield forecasts for Africa and Europe, with methodology discussions.