This was an installation I coded for Audi and HMC Interactive at the Goodwood Festival of Speed this summer. To get a decent frame rate, it was necessary to update the particle system on the GPU using shaders.
Some photos can be found here - http://16b.it/smoke
Looks like fun!
Which smoke simulation did you use?
Played around with various setups, Navier Stokes etc. In the end what looked best was to have some repelling particles along the boundary of the people. The force exerted by the repeller on the smoke particles is inversely proportional to the square of their distance apart. Each of the smoke particles has a random velocity, size and decay. The more force is applied to a particle the quicker it decays and its size also increases.