Skimmer Fly
Paragus ?
This photo probably lacks enough clarity to allow specific identification to genus and species. Eldoret, Kenya, January 2012.
If a Dipterist (a scientist that studies the world of flies, or Diptera) happens upon this page perhaps an e-mail will be sent with an identity.
A field naturalist could uncover some interesting fact about this insect by following to it's food sources and oviposition sites.