In the UK the National Archives has digitised the entire African section of the Colonial Office Photographic Collection, and made them freely available to view online.

The collection covers more than 100 years of British rule in Africa, dating back to the 1850s and including some of the earliest known images of Africa. The Colonial Office Photographic Collection contains 40,000 images, and the images taken in Africa represent about a third of the whole. Other sections of the collection will now be digitised.
In response the National Archives has launched a public outreach programme, making contact with communities who can help build fuller, more contemporary readings of the images. The programme has visited three areas so far, and has already thrown up some interesting responses.

You can view the collection on The National archives Flickr