blurring or ghosting or kind of clonning, looking for example and how to do

Hi, I only have cs3 so basically I can do this. I have been searching for a look but can't really find an example of it visually or how to do it. I am trying to do a video effect where you get a kind of ghost image following a person as they walk, so as they take a few steps.. kind of to give it speed. Actually if anyone read the comic the Flash, you know sometimes when they portray him running fast, you see a number of flashes with a kind of motion blur connecting them. Does this make scene, I know i have seen adverts where gymnasts do moves and you see all the proceeding frames of the move, like they put their arms up and each frame kind of remains in shot... something like that, or even just a few mos of an after image. Hope this is enough info and someone can help.

That is great, I looked these up and also the OKGO video effect for wtf which is kind of what I want. Basically I have a figure in a room and they are putting there arms up and down and out in two semi circles, so basically they are making the shape of an O with their hands. I am trying echo and looked at a tutorial online by the guy who did the ok go video, and they say to make the echo operator composit in front, though when I do this I dont see anything. Does the figure have to be cut out first or something...thanks

I only have cs3 is there I way I can still do, it doesnt have a rotro brush