Me and the family went on our first geocaching expedition. Basically your are give some coordinates in latitude and logitude and you have to use a GPS to find the cache. The cache is usually a waterproof container with a log book and some toys and knick knacks. When you find it, you are supposed to fill in the log book, take some toys and replace whatever you take with something of yours. Its actually pretty fun. I have been on two so far and it has been neat. More info at http://www.geocaching.com.