This is the base core IDEA... using wireless networking. Its using a RASPBERRY-PI Model-A the Faq is about the Model-B here http://www.raspberrypi.org/faqs (waiting on model-A, emailed them about other options) ALTHOUGH the Model-A ($25) has no built-in Ethernet and one usb port, so using a "EDUP EP-N8508" Wireless-N USB Wifi Adapter, (Linux groups says it'll work out of the box, don't know about Net-booting yet) it should be a wireless MOVABLE cluster.
Pretty neat... but i feel this will hamper computing speed, would still like to have a wired backbone.
Then all would be needed is a housing and power rails, done.
BTW, "EDUP EP-N8508 Nano 150Mbps 802.11n Wireless-N USB Wifi Adapter" at its lowest price $5.22 So for $40 a node you can build a pretty cheap scale-able cluster quick. Granted its not going to be blazingly fast without the wired backbone but the wireless aspect is kinda neat, the Model-B has too much useless stuff on it to go with the ethernet, but at $35 who cares.
That's what I am going to try and go with, just need to scrounge up enough to buy a Model-B and the ep-n5808. Also need to redo the power port of the R-Pi-A(B) to a more common power adapter, was thinking of using a IDE molex power connector and just forgetting about the 12v rails, things run at 5v and up to 700ma, so a standard desktop PSU at 200W will go a long way. Then I stress the wireless-N, the bandwidth won't handle 200 Model-A's screaming wirelessly, that's like 200 5 yr olds cleaning a living room (chaos).
ok, yea wireless would suck, i still need a 10/100 wired lan model-b