You can use Loopt Star to check in and receive awesome rewards, but the original Loopt has partnered up with Facebook Places to make it easier than ever to see where your friends are now. With the latest version of Loopt, you can check in to both Loopt and Facebook Places from one app. If you choose to "connect to Facebook" within the Loopt app, your posts and location updates will automatically populate on Facebook Places, including any comments or messages you or your friends post on your wall.
What's more, you'll see your current locations on Loopt's interactive map, friend history, and even Friend Alerts, which tell you when your BFF has checked in within 10 miles of you. The update is free, and is available in the iTunes store now.