I did learn there seems not be much done about it in Nan province, but that might change in the near future.
Of course there are many "geo caching" app's and web-sites. I am a member of Geocaching as ChangNoi1 and use the C:GEO app on my Android phone. Have a look and become also an GeoCacher!
Update : Now the first cache available in Nan town!
- "Now you are in the great City of Nan, here are a big amount of beautiful temples and the cache is at a place where you can find a lot of info about the beautiful sights in Nan. There is also a nice coffeeshop to have a rest after visit the gems of Nan. The cache is small, black and magnetic logbook and small pencil inside."