I delivered my talk at Tech4Africa (http://www.tech4africa.com) yesterday, on Geospatial MongoDB.
It went quite well, I think, with lots of folks coming to chat to me about it from many different spheres.
If you would like a copy of my talk, as well as the example code and SA data, it is available from https://github.com/paulscott56/tech4africa2013
You are more than welcome to download, remix and distribute the stuff with attribution, under a Creative Commons By attribute ShareAlike license.
I do hope that everyone in the room found my talk at least somewhat useful and enlightening!
Thanks to Tech4Africa for giving me the opportunity to speak!