I thought I'd tell the story of how I came to learn about this Wiki, because it isn't what you might expect...
A copy of what I originally posted on this can be seen in the Other Expeditions section here: http://wiki.xkcd.com/geohashing/2008-05-31_42_-71#Other_Expeditions
...but just in case that link gets edited or disappears over time, what I wrote was :
"dav0, Hi. I was out walking my dog in my sideyard today when three people (two young men and a young woman) show up in a black SUV asking permission to attend a "nerd convention" in the woods behind my house. They seemed harmlessly friendly enough, so I gave them directions down a path, around my shed, and down another path into the woods where they seemed to want to go. I warned them about the poison ivy, so don't blame me for any itchy side effects. I asked them how they found out about the "party" so that's how I ended up here. Interesting stuff. I'd be curious to find out whether these folks ever found what they were looking for. My address is 20 Birch Brush Road, Shrewsbury MA 01545, but the nearest GeoHashing meet-up location listed here would appear to be in Foxboro, MA, which is a good 45 minutes from here. What gives?"
So now I'm drawn into this bizzarro world and I guess I'm a little curious about whether these folks ever found their party, or whether they even had the right directions to begin with? I'll update this page with more information if I learn any interesting new tidbits.