Setting a "trail" on an actor that shows movement

How could you make a trail of sorts that moves and shows the movement of the actor it is following.

If I'm not clear an example would be having flames that follow behind a fireball and when the fireball goes upwards the fire is below the ball, when it is going up and to the left it is below and to the right, etc.

I think you could spawn partially transparent actors for it. The farer actor is the more transparent it is. You can then join them using stick joints.

That's an expensive solution for a simple trail effect.

Is the smoke from the jetpack in this game the kind of thing you're going for?   Basically it saves the last X positions into a list and then draws a circle (could really draw anything) at those positions, varying the opacity depending on how far away it is.

press W to use the jetpack

http://www.stencyl.com/game/play/2170

If you're still looking for this behaviour, have you tried After Image?