I actually moved to Kenya to help a friend setup a business there this year and had the good fortune of becoming involved with a number of NGOs of various sizes. One of the smaller startup style ones I was working with was http://www.earthenable.org where they are directly trying to bring down the child mortality rate dramatically by finding a really cheap and affordable way to ensure that families in Rwanda no longer have to live on a dirt floor (super prone to a lot of horrible diseases). They have some of the most impressive people I've ever met working on that project I seriously couldn't recommend them enough.