I use a Garmin Dakota 20 and I live in South Africa. I use GPS in off-road 4x4 driving and my primary goal is to map these tracks and also other tracks and minor gravel roads. Although I love my Garmin, one of the things that has annoyed me is that the map is difficult to change if any mistakes are found or to update the map when new roads are constructed. Openstreetmap.org solved this problem. I now build my own map with OSM data. It can be downloaded from http://www.andrew.nom.za/osa