Going back on my promise, I revisited my BitmapSmoke class and created something beyond cheesy. Move the mouse to position the heat/smoke source. Regardless, this one is all AS3 and was used primarily as a means to play around with displacement maps. The included Displacer class accepts a movie clip to displace and a map to displace it with, then updates the displacement every time you call run(). What's neat is that you can keep updating the map you passed in, thereby animating the displacement. Banners are looking better all the time.