As part of research for something I'm working on, I plucked out some statistics for mobile vs desktop for the world, and for South Africa. The numbers below are a guide to the state of play as at January 2014. The mobile / desktop split is a bit of a false dichotomy, but it's a useful shorthand for small things vs big things, new things vs old things.
Worldwide web usage is about 24% mobile vs 76% desktop. In South Africa, it’s more like 63% mobile vs 37% desktop. The tipping point (when it was 50 / 50) was around October 2013. It's important to remember that many users in SA are mobile-only: they don’t have access to a desktop computer with an internet connection.
In terms of the split of operating systems, the largest is BlackBerry with about 34%. Android is at about 20%, as is Series 40 (Nokia’s featurephone operating system). Symbian (Nokia’s newer OS) is about 6%, and Apple’s iOS is at about 4%.
Blackberry and Nokia are the handset leaders, but Samsung is also popular, taking around 15% of the handsets in SA.