Seconded. Africa is a bit of an opaque, far-off place to a lot of us, but the idea of going over there and sharing some skills definitely appeals to me.
Our charity www.rose-international.org is looking to have a basic web app developed that will allow local m&e of donor money that is used to pay for school fees (Tuition is charged for public schools here, and many kids are orphaned and have no way of paying the school fees).
We also aren't shy about sending people to Zambia to help out. If you're curious, or want more information, my email is in my profile. I'd love to hear from you.