Another hobby that I pursue together with my significant other Manuel is Geocaching.
Geocaching can me seen as a modern kind of paperchase, where you try to find treasures armed with a GPS.
It workes like this: on the Internet there are Geocaching pages like Geocaching.com where users upload the coordinates of so called treasures, aka geocaches or caches, they hid. Others users like me can than download these coordinates and search for the cache.
There are single-staged caches, where the only stage is the final. But although you have the direct coordinates, you still have to search for the treasure, because they are always well hid, so that no non-geocachers - also called muggles - would find and maybe even destroy the cache.
And there are caches that are multi-staged and you have to find out the coordintes of the next stage. There even are night-caches that provide a starting point and from then on they only work by using glow-in-the-dark-paint or reflectors.
My favorite are the latter because I like to puzzle and I like crawling through the woods at night getting the creeps...especially, when the supposed reflectors turn out as glowing animal-eyes ;)
When caching you have whole lot of exciting stories to tell, especially, when accidents happen (like tearing your cruciate ligament when caching in a wood on a hill, happened to me in May 2008 *g*)
Caching is a terrific outdoor hobby, where you not only need endurance and persistence but also brains :)