I'm sharing with you my mini-mod I made to my pc case, using some LEDs.
Now, before I start showing you the pictures I must tell you that before I made this mod, I had another that you might think it looked better.
Here's the video of it:
Those are 2 HDD activity Leds, that slowly fade off when the activity drops. To see how to make such a thing, here's a scheme for it (I modified it for only 2 LEDs).
The problem with those is that I discovered in time that they really bother me during night because of their excessive brightness. So I ripped the wires off, returned back to the good ol' red HDD activity LED, and installed 2 high brightness LEDs inside the case. I left the old LEDs in place just for the looks.
I connected them in parallel with a 56 ohm resistor for each LED, and mounted them on 2 small PCBs which I glued to the interior of the front panel. They are connected with a molex connector to the 5V line of the PSU.
One more thing, the big ugly holes you see are not finished yet, they must be rounded. They're for more air intake.