after playing with your code for a few minutes, I think I know the sort of tweaks I'll make: as I may have really long (and many) lightning 'shots' visible at the same time and still want them detaild, I'm going to use your code the way it was and make screenshots of it. those screens I'll edit (rotate/scale) and save as tga files. about 4 should be enough. then i'll use your code again and change just the particles to use these images, in combo with the streak flag instead of beam. So what I'm using from your code is the afterglow (awesome idea), the positioning of the particles (how you make them go from point a to point b exactly) and the look of the effect by generating the bmaps from it. I'll see how it works out.

I may post screens later, depending on how it looks.
Again, thanks a lot for letting me use this. You were already in the list of people I'd have given a "thanks to:" place (placement? placing?) in the credits, because you helped me with quite a few pieces of code before, now you've gotten a special place on those credits