This is a real simple thing - setup wise, but it looks so cool that I just have tell about it. I just finished building a watercooled dual Opteron 280 rig (that's 4 processors) and just added a 635 as a "finishing touch". I set up each of the 4 front panel LED's to indicate processor loading on a scale that starts at dark for 0%, through green, yellow, orange, and ending at red for 100%. It's just so cool watching the LED's "fluttering" through the color spectrum depending on the activity of the system services and applications I'm running. It's also cool to run 4 instances of Prime95 and watch the LED's lock up all red while the display shows the temps from my DOW sensors rising.