This new free service enables users to track flights in near real time and takes advantage of some of the new features of Google Earth 5.2. With this new feature you will also be able to download complete flight paths for individual flights and animate them to fly over their entire flight path. I’m guessing this is rather like the BBC’s iPlayer, a watch again service if you will.
Personally I don’t really see any benefit to this but guess is a nice gimmick to have.
Why not head over to Google’s Blog to see screen shoots and a bit of a guide to it.