Ran across this today.

http://www.youtube.com/watch?v=Z-gpwCspxi8

Now with that flocking algorithm I can see potential use for it in a game such as say Serious Sam. Could you imagine the swarms of opponents coming at you? Another scenario could be space combat sims or a game such as a driving game where you want realistic traffic flow though out a city. Of course there is also the possibility of using this in a RTS game as well where you have massive amounts of units.