Wow. I so want one... No!! TWO.

Nvidia's new GeForce 7800 GTX.

SPEC:
24 pixel pipelines
8 vertex shading units
430/600MHz Core/Mem clock with overclocking support.
302 million transistors
256-bit GDDR3 memory
PCI Express x16
Cost: base models about $600 up to the top of the line $1300.

I need two for this setup.

AlienWare's Dual graphics card support.

Yeah, about $4000.

It needs a 800watt power supply.

That will add a couple hundred a month on your utility bill.