I came across this wonderful BBC audio slideshow of old maps in Africa promoting this Royal Geographical Society exhibition.
Things about Africa you didn't know: The content is excellent, it explains where the name Africa comes from, explains why the Atlantic was originally known as the 'Black Man's Sea' and also makes an excellent point about the political power of maps: early maps showed the locations of tribes inland so the maps seemed full of people, later European maps showed empty spaces with color wash to indicate which European power controlled that area. People still lived there but the map makers wanted to show Africa as a blank land helping to justify their desires to colonise and exploit.
Simple Narrative is Effective: The presentation itself shows the power of simple, audio, slide show narration. There is no flashy 3D fly throughs, talking heads or 'cool' animated effects, just some music, audio description and the occasional annotation to draw the eye to the right location on the map. If you had just been given the maps as a set of layers to look at in GEarth you could have seen how the maps line up with current African geography but you would probably have missed the 'Ifrica' point they make, IMHO the narration adds a lot of value. Of course providing such a GEarth project after the presentation would have been fun as you would have got the best of both worlds: heard expert explanation but also been free to explore your own interests on the maps. This is an idea I've previously talked about in terms of GEarth tours and activities