Have you heard of Foursquare? How about Gowalla? Most people haven't. But just as Twitter has the major buzz right now, one of these two companies is likely to be the next superstar. They are kind of like Twitter, but with location tracking and game like elements mixed in.
I have played with both, as well as some lesser known location based apps and have had a hard time deciding where to place my bet. For now I am leaning towards Foursquare because they have a big headstart, have inked some big partnerships, and I know more people on Foursquare than on Gowalla.
This excellent infographic from Mashable shows you what they do and who has the advantage. Read the full article on Mashable to learn more about location apps and why they are next big thing.