But Foursquare is different, because it creates a new take on social networking by through local-based gaming that adds in the elements of GPS tagging along with localized loyalty rewards. As David King also notes, this new technology is worth exploring.
If you haven't explored Foursquare on your own yet, here's a informational slide deck to get you start:
How Foursquare Helps Consumers and Business Owners
* According to my twitter trail, my start date on Twitter was April 14, 1997