There was a time when a single computer would fill an entire climate control room. For example, the old Eniac took up 1800 square feet of space -- enough to fill a house. Today, you can fit more computing power in your cell phone and take it with you anywhere.
The glass house still exists, but now you can fit hundreds of blade servers and petabytes of storage in the same space. All that's lacking is the portability. For all that power, you're still stuck in one place. If disaster is imminent, or worse already struck and you need to get back up to speed quickly, you're in trouble.
News.com the other day mentioned a new portable data center from Rackable. With it, you can pack 1200 servers, racks, and cooling equipment into a package the size of a shipping container, slap it on the back of a tractor trailer, and take it with you wherever you go.
The Rackable portable data center is probably overkill for a local LAN party, but it looks like it might be a good alternative to get a data center on its feet again or out of the way in a hurry.