Very short part... very small detail :)
While browsing for interesting component, I found the "Logisys Red LED Lighted Computer Case Feet". They are replacemetn feet who can fit on most PC case.
I had to grind a little bit each of the hole of my case in order to fit them.
Basicaly, It's a transparent plastic feet uin wich you can place a led (from the interior of the Chassis.
PRO: original, can be customised if you get different led color, about no power drawn and no heat generated. Silent.
CON: more wiring inside the Chassis, got to keep that in mind lather if you want a clean interior :).