check-in

Before Facebook goes public next year, it wants to know a bit more about what you do when you're out in public. The social networking giant is acquiring geo-social app startup Gowalla.

Check-in service Gowalla was always prettier than mobile social network leader FourSquare, but it still could never catch up with its rival. Its new version, Gowalla 3, could change that: It allows users to easily check in on multiple social networks and track friends across them. Goodbye, check-in fatigue; hello competition.

San Francisco local ratings giant Yelp rolled out a new offering last week that allows merchants to provide rewards or discounts to Yelp users who check in at stores or restaurants. This move has been long anticipated as Yelp battles FourSquare.

Check-in phenom Foursquare just passed 3 million users, a milestone that cements its growing lead in mobile social networking. But how did it outrace competitor Gowalla, which was born at the same time and with arguably better technology? By having the right real world social networks, of course.

These days shopping without a loyalty card for anything from groceries to consumer electronics will result in a higher bill or missed rewards. But to take advantage of every loyalty offer you need a key chain that weighs as much as a shotput. That is until you digitize your loyalty cards with an...