Here is a simple peice of ActionScript that can also be used to create snow or rain. I've seen a few particle engines on the net that I easily could have used but I wanted something simpler.

So this is what I came up with.

var total:Number = 30; //total number of bubble
var sw:Number = Stage.width; //stage width
var sh:Number = Stage.height; //stage height
 
for (var i=0;i<total;i++){
 
     var bubble:MovieClip = this.attachMovie("mcBubble",
     "mcBubble"+i,this.getNextHighestDepth());
 
     // set the initial random speed
     bubble.yspeed = random(500) + 3;
 
     // set the initial random position
     bubble._y = sh;
     bubble._x = random(sw);
 
     // set the initial wobble factor (the X movement)
     bubble.xspeed = random(3);
 
     if (random(2) eq 1) {
          bubble.xspeed = -bubble.xspeed;
     }
 
     bubble.onEnterFrame = function(){
 
         // the bubble movement
         this._y = this._y - this.yspeed;
 
         // check if the bubble is out of the top of the screen
         if (this._y <= -15) {
 
             // then reset to the bottom
             this._y = sh;
             this._x = random(sw);
             this.yspeed = random(5) + 3;
 
            // now to randomise the scale of the bubble so
            // we get a few wee ones too
 
            scale = 2 + (random(8));
            this._width = scale;
            this._height = scale;
 
            // set the initial wobble factor (the X movement)
            this.xspeed = random(3);
 
            if (random(2) eq 1) {
               this.xspeed = -this.xspeed;
            }
         }
 
         // change the X value of the bubble
         this._x = this._x + this.xspeed;
 
         // the bounce code for either the left or right of the
         // margin for the bubble
         if (this._x > 100 or this._x < 50) {
             this.xspeed = -this.xspeed;
         }
 
      }
 
}

Easy.. now this is what it looks like.

You could make it more realistic by tweaking the speed, wobble values and add blurs or better graphics but what I needed  it for, this is perfect.

Download the Source Code - Use it any way you want, just let others know how you used it by leaving a comment. Peace!

Enjoy.