Best Data Center Mod?

One of my guilty pleasures these days is spending an evening browsing through Make magazine and dreaming of a day when I’ll actually have the free time to build a stun gun-powered potato cannon.  And while cruising the Make web site recently, I came across one of the most interesting custom PC cases (known as “mods” by those who indulge in the craft) that I’ve seen.

And that got me thinking: What’s the coolest mod ever in a data center? I’ve seen some awe-inspiring data centers over the years, including a few that would give the imaginations behind sci-fi movies a run for their money, but these were cool because of their size or security or location. Surely someone out there, in a fit of boredom some evening or rebellion against the rack-after-rack monotony, has modded their data center in some way? Maybe a couple neon-lit fans in a rack near the back of the room? Maybe a few hundred feet of light-up cabling? Maybe I’m out of my mind?

So I’m asking: What’s the coolest data center mod you’ve ever seen or heard about?  If we get enough interest, we might even morph this into a contest with prizes like…oh, heck, why don’t we start with the slightly used AMD64 lava lamp on my desk. (I’ll need photographic evidence of the mod before the judging will be official. Prizes will be given at the sole discretion of the judge, aka me.)

Show me what you’ve got!