Just saw this over on Bink.nu.  It turns out (and I have verified), that there is a pretty cool easter egg included with the HP EX470/EX475 MediaSmart Home Servers.  The HP servers have a series of LEDs on the front of the unit that turn different colors to indicate status at a glance.  With the easter egg, you can set the lights a'blinkin with different patterns.

• Fire up the Windows Home Server Console
• Hold down the Ctrl + Alt + Shift keys and click on the picture of the computer next to the LED brightness control.
• The control changes to "HP MediaSmart Server LED Light Show"

You can now select from the following options:

-Default System Lights
-Holiday Lights (perfect for this time of year)
-Descending Chasers (in blue, red or purple)
-Ascending Chasers (in blue, red or purple)
-Pulsing (in all colors)
-Night Rider (in all colors)
-Morse Code Credits

Video of the LEDs in action over at Youtube.