Patience and a generous budget will be necessary to get you one of the first announced quad-GPU desktop PCs. Alienware has rolled out the Area-51 ALX "CFX", which will be available with up to four ATI Radeon GPUs. The PC will cost at least $5649 with two HD 3870 X2 dual-CPU cards, an overclocked (4.0 GHz) Core 2 Extreme QX9650 processor, 2 GB of memory and two 10,000 rpm 160 GB hard drives. If you order it today, Alienware estimates that you will get the system in about eight weeks, on April 24.
If you don't want to wait that long, you could opt for a 3-way SLI version of the PC, which, however, is only available with a 3.33 GHz QX6850 processor. This system will ship by April 4, according to Alienware, but cost you at least $6400.