I can speak a bit from personal experience. I just spent close to 3 months in Rwanda and one of the coolest things I found there was an incubator called kLab in Kigali (www.klab.rw) that was modeled after incubators they have in Kenya. I heard from some ex-pats who lived there that one of the main problems affecting the ICT industry in Africa in general is that you can go through the CS programs at their university and never touch a computer. Many teachers don't have the programming chops and their students can't do anything about that, so anyone who does know how to code either learned on their own, or learned outside of country. At kLab they love Udacity and run study groups where students and former students meet up and learn Python and work on project/homeworks together (they have a demo night tonight in fact.) They also have all sorts of regular meetups for web apps, entrepreneurship etc.

Another thing about Rwanda that is surely affecting their growth and blows many African countries out of the water is they have wired most of the country with Fiber where most have dial up speeds. It is not yet common residentially, but for global businesses to establish a base in East Africa, this is huge. I lived two hours outside the capital in a mud house with out running water inside, but I did have 1-Mbps download (was near a rural, well-financed hospital, but still, it was faster internet than I had in Boston.) This is largely all due to the government there which is a pretty well-oiled machine with a bit of a benevolent dictator, but one who gets things done for the benefit of the country IMHO. Contrast with where I am currently living in West Africa in Sierra Leone where the infrastructure is dismal and there is no kLab type place anywhere. There is a lot less action in the startup/entrepreneurship scene. Bad infrastructure, a long civil war and countless other things feed into this.

In terms of startups...so much of Africa runs on mobile phones (the majority of small amounts of money is transferred via SMS) and most of what I saw in terms of startups was based around Mobile-Social-Local. Not unlike what you see in the US and elsewhere.