Geo-location services–mobile applications that allow users to share their physical whereabouts with their networks–are quickly gaining momentum. Checked-In gives you what you need to know to both have fun with geo-location and profit with front-runners in this race Foursquare and Gowalla. Jammed with useful and easy to follow information, Checked-In covers how other new players in the game (as well as some old hats) will likely change the landscape and what you can do to stay ahead of that curve. We take you from start-to-finish, showing how to begin with these applications and how to make them work for your bottom line. See how these new social media powerhouses can propel your local and national marketing forward and keep you ahead of the pack.