Has anyone here heard about the new data storage medium that is being researched? Apparently it'll be able to store up to 3.9 terrabytes of data, which is insane. Anyway, I checked out this article on Wikipedia to see how it worked... http://en.wikipedia.org/wiki/Holographic_Discs ...and I don't quite get it. Here's what I can gather... there are two layers on the HVD, one which is read by red laser light and contains 'servo' data, and above this is a layer with normal data on it, read by a green-blue light. The red light passes through the normal data layer, so there's no interference or other weirdness. But what I don't get it... how does simply storing servo data on a seperate layer manage to free up 3.9 TERRABYTES of data? The green-blue light has a longer wavelength than the blue laser light used to read Blu-ray discs, and they can't store anything near the amount as HVDs will. So what's going on? And what *exactly* is servo data?