Space Tag's creators have studied the human brain and even the Sahara Desert ant, to develop a social navigation and mapping system that's built on crowd tagging.

An new iPhone app called Yellowbrck is trying to become the Foursquare for parents looking for fun activities with their children. Just like Foursquare, YellowBrck comes complete with check-ins and badges – but the best part is that parents can actually earn coupons and reductions at stores.