Rain/snow resourses

Hi guys!
Have anyone seen some articles or resourses how to simulate rain/snow using vertex programs/fragment programs?
Thanx in advance

There’s an article on this website (opengl.org) - “Advanced Graphics Programming Techniques Using OpenGL” (search for particle systems/precipitation). Also, there’s Mark Kilgard’s article on OpenGL extensions, and it contains section (and source code) for point parameters extension demo - I think this is how they do snow at least.
URL for this is: http://www.opengl.org/developers/code/features/OGLextensions/OGLextensions.html (pointburst.c).
I hope this helps,