CTA Bus Tracker API
The Chicago Transport Authority has a really cool real time Bus Tracker that shows bus routes in Chicago and the real time position of buses in the city.
Harper Reed has managed to work out how the map makes calls to CTA's underlying bus data and has built an API on top of the data. This means that anyone can now produce their own mashup using CTA's data.
One example of a mashup built with the data is the CTA Bus Tracker for iPhone and iPod Touch. Also created with the API is the Chicago Bus Tracker Widget.
Ryan A Graves.com also has a really cool article on how Harper went about hacking the CTA Bus Tracker Map.
Via: Programmable Web