You can go to Thriving Family and get your own map, passport and travel guide to print out to do this with your own kids. (We also discovered that MY subscription to Thriving Family actually contains the fold-out map ... which I'd probably have noticed had I been up-to-date on my own reading.)
Anyhoo, the idea is you read about different countries all around the world, a biblical application, activity idea and prayer for the people of that region. Then the kids can put the applicable stamp in their passport book. We printed out the travel guide and made each child their own passport. I printed the custom stamps on label paper, so they can really stick them in their booklet.Thriving Family website to check it out and take your kids on a worldwide mission trip!