While spelunking the interwebs last night I stumbled across this gem from history.
In 1930 a device was invented to help with car navigation. Connected to the speedometer, it consisted of a paper map that scrolled at the same speed as the car. In theory this would keep the map updated with the exact position of the car.
One of the major downsides to the device is that if the car turns, the driver (or his navigator) had to swap out to a different set of maps, and manually set them to the right spot on the map before setting off.
It also makes me wonder how far off the map gets if the car experiences wheel spin.
This clearly predates geocaching, which started in May 2000. However it seems like the perfect creation for those letterboxers out there (a hobby which started in 1954.)
There isn't a lot of information on these devices on the Internet (it even lacks a wikipedia article), but these links will give you a bit more information (tho a Google search may also help):
Iter Avto - The world's first automobile navigation system (1930) [dieselpunks.org]