In July through September of 2011, the Africa Soil Information Service
(AfSIS) ICT4Ag team conducted a socioeconomic survey in an area west
of Arusha, Tanzania using Open Data Kit. The video at
http://www.youtube.com/watch?v=afrxy8rIn2M highlights the experience
of two enumerators who worked on the project.
If you want to find out more, the AfSIS ICT4Ag blog at
http://africasoils.net/labs/ict4ag/ has lots of great posts on using
ODK for agricultural data collection.