This video is pretty old now (2 years), but still a really great example of using Trapcode Partciular. The slow moving rain was added. Text from the vimeo page:
"Second and final slow motion test...It was filmed months ago. Editing is rough because I don't have time to work on details.
Edited with Twixtor in After Effects.
Rain was made with Trapcode Particular 2 in AE
Lens used: Canon EFS 18-135 mm
Shutter speed: unknown
Composer: Niklas Aman, STIM
Publisher: Brusbox Music STIM
Check out Niklas' awesome music: