Lightning using displacement.. help

I was trying to replicate something like the lightning demo here:

http://www.scirra.com/demos.php

But that seemed like it would be way to much for me to figure out for what I needed it for, so I came up with this:

http://dl.getdropbox.com/u/666516/zap.cap

Using the displacement map, you can set the x,y anywhere you want, so it's a lot easier to set up.

Note you cant change the sprites angle, or it messes everything up.

Any way if anybody feels like giving me some pointers on how to refine this even more, or how to make it more realistic, please feel free.

Hmm noone's interested?

Oh well, I've made a bit of progress on my own, link up top's updated.