Karen organized a regular international pot-luck dinner for friends we met raising our children. This turned out to be more about the food and each other's company than keeping track of our children's lives.
See W4 Wiki
We remembered what cuisine we'd chosen for each dinner on the wiki. We also allocated dishes so we had variety without duplication.
Popups on the google map showed a paragraph from each geo-located wiki page along with a link to see more.
Ultimately we needed help remembering where in the world we'd been so we could choose our next cuisine. I wrote a cgi script that read pages looking for (lat, lon) pairs. I placed these on a world map with popups that copied the title and paragraph from the wiki page.