Array Annimations

I forget what they are called. I have seen quite a few of them over the last few months and ive wanted to create one for some time. Something like what they have on the big screens at Raves or Nightclubs. Where you have sinchronnised patterns of light following certain paths, fading into different shapes etc. I know they, well i think they are done with arrays somehow and maybe paths but not too sure. I remember i actually had it down pat few months ago as to how to go about making one of these, so it couldn’t be too difficult but now i have no idea. Can anyone help or post a link of some kind just to get me started.
EDIT: This isn’t exactly what i ahd in mind but along the lines of what i would like to do. Any tutorials for something like this?,item,3738656210.aspx
Is it all done with IPO?

Take a look at .

Thanks for the link.
The blend seemed quite elaborate at first. I mean i have to study it more and he uses things i haven’t seen yet, like a ‘layer’ in the IPO but roughly what i see he has set up arrays parented to empty’s using ‘object offset’ in the array modifer, would that be correct to say? Im also not sure how his used, or not used key frames becasue the IPO is bare for all objects (or has he recorded all movements somehow?) As i said, ill look at the .blend more and see if i can work it out.