Trip Advisor - Cities I've Visited
This Facebook application from TripAdvisor lets you create a Google Map of locations around the world that you have visited and then share your map with your Facebook friends.
You can change the map markers on the map to show that a location is a favourite location, a location you can advise friends about or even just a place you are planning to visit. You can also create a Favourite Destination list from the places that you have visited.
Trip Advisor's application also lets you create a Travel Photo Guide by connecting your map with one of your photo albums saved on Facebook.