Lots of people use maps on their Facebook profiles to show you where in the world they've been. Like an overstuffed bookshelf, they're basically just another way to show off. More useful is a compact app called Dopplr: Where Next?. Instead of flaunting where you have already traveled, Dopplr helps you meet up with friends who may be going to (or already live in) one of your upcoming destinations. For now, this widget is available only on Facebook, and you need to sign up on the Dopplr website to make the app work. It doesn't look like much, but it's a lot smarter than many of the other travel apps we've seen. So, where will you be going next?