Where Do You Go provides Foursquare users with a dynamic heat map of the places they have visited on top of a standard Google Maps interface. Users can create static snapshots of their maps and then share them on Twitter, and these maps will self-update automatically in the background as users continue to visit new places and checkin with Foursquare.

(Note that user privacy is protected because recent data is not shown and because individual check-ins are aggregated into an imprecise heat map.)

http://lehrblogger.com/2010/03/19/where-do-you-go/

This project has gone on quite a while longer than the quick hack I intended it to be, so I apologize if the code is a bit of a mess. To create your own GAE installation of Where Do You Go you'll need to modify constants.py (and create the gitignore'd oauth_secrets.py) to contain the Google Maps API key and Foursquare consumer key/secret for the domain(s) you're using. Many thanks to Thiago Ganzarolli (https://github.com/tganzarolli) for updating the app to work with v2 of Foursquare's API!

Feel free to contact me if you have any questions!