Join OpenStreetMap UK

OpenStreetMap is the world’s premier provider of free-as-in-freedom mapping and routing data, with a data density in many places which far surpasses all proprietary providers. Here, for example, is the centre of Kampala, Uganda, Africa:

They have chapters around the world, and one was recently set up in the home of OSM, the UK. Joining is only £5 a year; please consider joining and supporting them in this way if you use OSM data at all or are interested in the project.