You could use the outline webGL effect. You'll have to get it from this topic and put it in your installation folder.
See attached capx for an example...
[attachment=2:2rksig8z][/attachment:2rksig8z]
Now, if the effect you after is a blurred additive glow, you'll have to use a different sprite on top of the spaceships and set its blend mode to additive.
See the following capx...
[attachment=1:2rksig8z][/attachment:2rksig8z]
quote]
You can use glow mask on photoshop.
2 mask's on in 100 opacity and the other 80 opacity.
Like this:
I think i got it guys, you gave me an idea, since i can´t use photoshop i decided to use Gimp (which is similar) and i found a neon effect so i made a neon version of the sprite (the outline) and placed the normal sprite on top of it. Now i just need to adjust some values.
Thanks a lot for the help!