PFlow Collision Shape world-space modifier applies simulation properties such as bounce, friction, and collision shape to mesh objects so they can participate in the simulation.
Particle Skinner modifier lets you apply particle motion to any mesh object, and break or tear the object into pieces when particles move apart. It's applicable to a wide variety of simulation situations, but is especially effective when combined with the PhysX Glue test.
Particle Face Creator is the special-effects artist's dream machine. This modifier works with Particle Flow to let particles moving past a mesh surface hide and/or reveal parts of the mesh on the fly, based on proximity, with natural-looking edges thanks to its ability to subdivide the mesh dynamically throughout the animation.