AnthroSpace

The AfricaMap project out of the Center for Geographic Analysis at Harvard aims to address an increasingly relevant problem of social science and humanities spatial research: how to build an infrastructure to manage the spatial data. 

From the website:

Despite the existence of excellent public maps for Africa, to date there is no common source that allows students, researchers, and the general public to:

1. Interact with the best available public data for Africa
2. See the whole of Africa yet also zoom in to particular places
3. Accumulate both contemporary and historical data supplied by researchers and make it permanently accessible online
4. Work collaboratively across disciplines and organizations with spatial information about Africa in an online environment

Applying open source standards it makes use of OGC (Open Geospatial Consortium) compliant web services such as WMS (Web Map Service), emerging open standards such as WMS-C (cached WMS), and standards-based metadata formats.

The Landscape Analysis Tools Portal maintained by the USGS provides access to spatial data in connection with a wide-range of landscape analysis tools.

The Southern African Human-development Information Management Network for Coordinated Humanitarian & Development Action(SAHIMS) publishes free GIS data for a number of African countries. From their site:

SAHIMS GIS Data server offers easily accessible standardised data provided by various United Nations, non-governmental organisations and government agencies. Datasets in this catalogue are downloadable without any charge. It can be viewed and manipulated by using most popular GIS software. Metadata is attached to help the user have a better understanding of data sources, applications and copyright.

And from the SDI-Arica (Dec 08) list comes the pointer on weekly exports of OpenStreetMap Africa as shapefiles (and Garmin)