While grazing on the tube this evening I happened to catch the opening of the first vignette of the Twilight Zone television show. It seems some college students were competing in the Great Internet GPS Treasure Hunt (or some such). They appeared to be using Meridians that had no satellite locks.
They found the treasure they were looking for. Of course it was buried. Expecting it to be a collection of CDs it turns out to be an Aztec chest with Twilight Zone consequences: the sun disappeared.
Just another thing to watch out for while geocaching.