Tired of UberGeeks kicking sand in your face when they whip out their twin Xeon processor PC? Well, just wait until you see the envy when you slide this Orion 96 node box from under your desk. That's right, 96 processors, 150 gigaflops sustained (300 peak), 192GB of RAM (192 gigabytes of RAM?!?!?), and up to 9.6 terabytes of disk storage. All in a box that's not much larger than your run-of-the-mill server tower (Okay, maybe a little larger than your standard full tower case. The point is it's in a case that you can plug into any wall outlet, flip one switch to turn it on and doesn't require a team of workers to keep it running).
It runs the Linux 2.6 kernel (you didn't think this would be running Windows XP Home now did you?) and includes the "standard parallel programming libraries, including MPI, PVM and SGE." [I think I got the links right but I'm not into cluster programming so I could be wrong on some of them.]
If the thought of selling your house to afford one of these ("priced at less than $100,000") is beyond what you want to do you can instead get the 12-node version ("priced at less than $10,000) that sits on your desktop. Note that neither is currently available for purchase although both are slated for release Real Soon Now.