Nice to hear that you are coming to Africa to teach s/d. Which country are you planning to visit? Am located in Kenya. Here we have Ihub centre and community that you will meet hackers. Never heard of an ONGS that facilitate, but maybe you can research alot. Also you can start your ONG. Best Luck!
What are ONGs? I would encourage you to visit Kenya and consider teaching at Strathmore university or at one of the hubs. Commenter tatucity (http://afritech.org/user?id=tatucity) always says that the developers at the local hubs will never produce the next zynga or Facebook because they do not have the skills to produce software that scales. Email me privately (jkuria gmail) and I'll put you in touch with someone at iHub and Strathmore University.