I regularly use BORIS FX (just Google it). You will pay, but the plugin for After Effects has a ton of cool effects, including snow, rain, etc. You can adjust all the parameters of the rain, like size, opacity speed, angle, amount, depth, on and on.

[QUOTE=Jesse Redman]
I looked at Particle Illusion SE and will probably download 3.0 to try to see if it can produce similar results.[QUOTE]

Jesse,

"There's a good rain emitter in the July 2004 library."

I found it the other day, it is good to learn from and a good place to start to make your own.

Bill

Bill,

Pardon my ignorance, what is the "July 2004 Library"? Is it on DVi?

Thanks in advance,

The library is available as a download from the ParticleIllusion site.
Here are all the 2004 libraries for example:
http://www.wondertouch.com/dl_thumbs_2004.asp

I've had PI for quite some time (longer than I've used Shake or AE) and still use it quite often due to it's speed and ease of use. Great tool.