@TeamMCS -- If the wedding is in England, I will happily attend. 
@Everyone -- thank you very much for the kind comments.
I just have to share the news of what happened next with this project. Last Thursday (the 17th) I gave a little 20-minute presentation about the "Reverse Geocache Box" over at the monthly Austin Dorkbot meeting. On Monday morning, a fellow from MAKE magazine posted an article about it on the blog. Around the same time, Hack-A-Day saw my posting here and posted an article. These were then picked up by Gizmodo and Engadget and finally... well you can read here to find out what happened next.
http://arduiniana.org/2009/10/puzzle-box-chapter-2/
Thanks again for all the kind support. I really am indebted to all the smart and helpful people on this forum.
Mikal Hart