iToo Software have released version 2.2 of their RailClone plug-in for 3ds Max.
3ds Max Particle Flow Tutorial - Barn Tornado
Pete Draper has made an 11-part tutorial on creating a tornado using Particle Flow in 3ds Max.
Agent - Crowd Simulation Plug-in for 3ds Max
Geoff Samuel has unveiled Agent, a crowd simulation plug-in for 3ds Max, that is still under development.