http://www.omniaaudio.com/tech/lookahead.htm

This page is pretty clear on the basic idea...

While you might think a "look ahead limiter" makes a lot of sense? That's not always the case. In fact, I find that look ahead limiting can really destroy the impact because it already knows when the impact is coming. But for broadcast purposes and other applications, a look ahead limiter can prevent any "overs". That doesn't ensure the fact that a look ahead limiter is better than a conventional "let the peak through before I react" limiter. In fact, that's frequently what I want. I want that initial peak to slip through. And then it compacts the rest of the meat. In fact I count on that happening. People only created look ahead limiters because they are control freaks. I'm an out-of-control freak. And that's why my recordings are so good. My out-of-control controls are highly controlled by my out-of-control instincts.

Thinking around the box. Around and around and around surround.
Ms. Remy Ann David

Remy woke up pretty inspired. :)

I don´t think look ahead is all that bad once you can control the time period of the predictions. :)

I like PSP Xenon and TC MD3 TDM.
People also talk about Elephant, L3 and Sonnox.

Thanks for the replies. I have to confess, after reading the responses and the link, I am still a bit foggy on the concept, perhaps because I cannot grasp the two other potential states, look simultaneous and look behind, and the latter probably requires travelling backwards in time to function properely, thus it may only be applicable in some other Universe.

I am however confident that with a more time, thought, and reading, the concept will eventually gell.