The Hat Game
The Hat Game is a modern version of the children's game tag, only with a bowler hat. The game was created by Simon Games and is currently being played at the South by South West Interactive Festival in Austin.
The game revolves around a GPS-equipped bowler hat which people can follow in real-time on a Google Map. If by using the map you can track down the hat wearer you need to say to them 'Excuse me, I do believe you have my hat!'. They then need to pass the hat onto you.
The person who wears the hat the longest each day wins a prize. Of these, the one who has it the longest over the weekend of SXSW Interactive wins the big prize.