wondertouch has released a new effects plug-in for Motion users called Particle Emitters. Particle Emitters is a particle effects library designed for creating smoke, explosions, and a variety of other organic, animated designs. The Emitter packages ship with up to 337 different effects in three different allotments.
You can find more information about the Particle Emitters for Motion at the wondertouch Web site. Particle Emitters are available for US$39.00 for 65 emitters, US$99.00 for 200 emitters, and US$149.00 for 337 emitters.