Just released... After several months of work, Petter Batty has announced the release of the Whereyougonnabe application for facebook users. In a nutshell... The key idea of the system is that you and your friends tell us where and when you will be doing things in the future, and we look at this information to tell you when you will be close by to your friends. The app can also be integrated with Google Earth. USers register on facebook and add the app, then you jump to the apps settings and start adding posts about "where you will be", friends and colleagues can then track your movement and see your calendar... nice! Looks like Peter, James, Jason, and me are on there testing it out right now. See more on Peter's Blog
See also on facebook at http://apps.facebook.com/whereyougonnabe/
Introduction to whereyougonnabe from Peter Batty on Vimeo.