I call this a Jet Engine Particle Effect, but can be used for many things. Would be good for flame effects coming from 'engines' or 'exhaust'.
Script is mono compiled to potentially reduce lag and script is full permissions so you can mod, copy, resell as you see fit.
The screenshot gives you a basic idea, but screenshots don't show particle effects very well, but I took a screenshot of the particles in different positions to give you an idea.
Any questions or comments feel free to drop me a notecard.
See item in Second Life- Full Perm particles mod as you see fit
Worthless
This particle effect is totally worthless: it rotates depending on the angle at which you look at it, meaning it can not possibly create an effect useful for appearing as fire coming out of a rocket engine. When you look at it from certain positions, the fire suddenly goes out sideways - which doesn't make for a very convincing rocket!