some simple snowflake code

snowflake.as

import flash.display.DisplayObject;
import flash.display.MovieClip;
import flash.events.Event;

var PARTICLES:Number = 60;
var OPACITY_SPEED:Number = 20;

var snowFlakes:Array = new Array();
var snowFlakesProps:Array = new Array();

var STAGE_WIDTH:Number = 400;
var STAGE_HEIGHT:Number = 600;

addEventListener(Event.ENTER_FRAME, function(event:Event) {
	for(var f = 0; f < snowFlakes.length; f++) {
		var t = snowFlakes[f];
		var o = snowFlakesProps[f];
		
		if(t.y > 0) {
			t.alpha -= .01;
		}
		
		if(t.y > STAGE_HEIGHT) {
			t.y = -10;
			t.alpha = 1;
		} else {
			t.y += o.sp;
		}
	}
});

for(var i = 0; i < PARTICLES; i++) {
	var s = new Snow();
	s.name = 'flake_' + i;
	s.x = Math.random() * STAGE_WIDTH;
	s.y -= Math.random() * STAGE_HEIGHT;
	
	var o:Object = new Object();
	o.sp = 1+Math.random()*2;
	o.wi = -1.5+Math.random()*(1.4*3);
	snowFlakesProps[i] = o;
	
	addChild(s);
	snowFlakes.push(s);
}