HDDs always say somewhere on them do not cover this hole. However that only makes me want to plug it up and then laugh for a good 5 minutes like some evil genius from a movie.But really what the heck is this hole for? If it allowed dust to get in then the drive would fubar so then how can it be used for anything?I have plugged it before on two old 40gb hdd that I wraped with duct tape to fit into a ramen box and.... they worked fine. Its not like covering the hole made the drives implode or anything.My only two guesses are that they allow it to cool better, but then again how could one little hole that cant allow dust in cool anything for #$%^, or that it allows the drive to equalize pressure with the outside.so my question basically is what the heck is the hole for and does it matter if you cover it?