You may not have heard of Google's Innovate or Die competition, but it was a $5000 contest for coming up with a method to provide rural communities with water—an endeavor that doesn't sound glorious, but is quite important to thirsty people. Aquaduct, the winning team, created a bicycle that can both help transport water quickly and easily, but clean that water at the same time! Congrats to Aquaduct, whose team of 5 easily averted a tense situation by being able to divide up the prize with simple math. [Google - Thanks Diem!]
I never visited Africa... I was born there and grew up there. Granted this is not suitable for every situation, however Africa is a big, big continent. There are places where roads are more suitable, but water is still terrible. Not only that I think we far to often underestimate the ingenuity of repair jobs in african countries...Who knows this could create employment for small repair "shacks."
I don't think this is the only solution, but it's a brilliant start. I think it will need multiple concepts for differing needs... for example the straw that purifies as you suck on it. There are various organizations trying to raise funds to distribute these. We can be pessimists, but then we don't move forward at all.