I really enjoyed Measuring the World (in German: Vermessung der Welt) by Daniel Kehlmann. It describes how Alexander von Humboldt cartographs southern America and how Carl Friedrich Gauss finds out loads of miracles of the world of mathematics (and later uses these to measure out western Europe). The book is really good in giving you the feelings of those days – how it was being a discoverer.
You can have those feelings now, in our present. There’s OpenStreetMap, a Wiki-like community project for street maps. Everybody equipped with a GPS device can record tracks and use a software on her PC to tag those tracks, e.g. with street names, to then upload the track to their server which will combine all those tracks. The resulting map is put under a creative commons license and hence, it is free for all of us to use.
Many streets have already been mapped, but there are also millions of white spots right now – check out Munich (DE), for example – so join in and help measuring the world!