Following on from some previous posts on the spread of pandemics (1 and 2) such as the swine flu (H1N1) and the recent article in Nature by Joshua Epstein from the Center on Social and Economic Dynamics. I just cam across this movie (below) which explores these issues in a easy to understand way.
The Brookings site is also worth exploring for those interested pandemics and public health.
There is also this spatial model from the Los Alamos National Lab who have modeled Avian flu on a supercomputer which explores vaccine and isolation options for thwarting a pandemic. Full details about the work can be seen here.
On a slightly bizarre side note there was also an interesting article on the BBC entitled "Science ponders 'zombie attack'" where researchers from the University of Ottawa showed if zombies actually existed, an attack by them would lead to the collapse of civilisation unless dealt with quickly and aggressively. The full paper can be read here.