Some (non-photorealistic) particle and fluid tests using the new Cycles render engine.
I tried to use the speed vectors of particles to distort the barground with a vector blur node. I also used only the speed values and not the actual shading to display the particles.
A had to test my new hardware a little. There are not more than 2.400.000 particles visible at the same time, though.
Dispersion and caustics rendered with the internal render engine of Blender 2.5 + explanation.
A small compilation of visual effects made with Blender 2.55 Beta. The animations are only experiments I made to evaluate the new possibilites with Blender 2.5.