Viral spread visualized, update

Viral spread of Facebook app from Stew on Vimeo.

The movie above is a (blurry when streamed, try the 3.6mb MPEG download) visualization of the signup and invite data from Bookshare from July 18th of last year to now. As users sign up they are geolocated and plotted on the map. More users signing up in a particular location mean bigger, brighter spots. Invites from one user to another are drawn as snaking lines that travel from the city of the inviter to the city of the invitee.

It's written in Processing.

I'd love to hear from anybody who owns a large Facebook application and has kept id / install date / invitee data (bearing in mind Facebook's data privacy rules...). See also this.

First draft available here (1.6mb MPEG)