This old chestnut has been around for ages. However, it’s suck a good one, I’d put it in for the sake of reference in case folk haven’t seen it.
http://wiki.eth0.nl/index.php/LackRack
You know Ikea’s standard cheap coffee occasional table, Lack? It just happens to be just the right width for a home hacked server rack! Perfect for re-purposing old rackmounted kit that might come your way that would otherwise go to waste.
Massive props to eth0.nl for a genius bit of practical hackery.