Alternatively titled: "How to build a desk toy that functions better as a conversation piece than a practical replacement for a Hyper-V/Xen lab"
There's nothing wrong with conversation pieces. Many stories here are, and funnily enough they tend to lead to good conversation. May there be more of them!
Real Pi clusters get posted every month or so, there is more required than an albeit cute rack case and improvised small PDU and switch.
Probably one of those.
* Have you done a write up?
* What software do you run to make it a cluster?
* What problems are you running on it?
* What have you learned by building it?
* What problems did you have?