Actually there are two tutorials, the first shows how to make a simple model of a snowflake and the second shows how to replace particles with the snowflake model. The tutorial shows how to alter the settings of the particle system and the collision properties of an objects hit by the snow to make the effect realistic or fun.
Click here for the snow page
In versions before 2.55 adding the ‘Follow Path’ constrain was enough to make an object follow a path, inserting key frames was not necessary. Adding key frames gives an interpolation curve that can be edited to give fine control over the animation.
I have had an email from dvegamar who showed me a way of following a path without key frames that works in 2.55, go to the page for the details.
I have just uploaded a new tutorial that creates a set of bouncing balls. The set of balls are created using a particle system and the bouncing behaviour is modified by adjusting physics properties. For more information and the Blender file go to the tutorial’s page.