The research group ASTRA, part of the Vision Lab of the University of Antwerp, has constructed a computer "made completely from consumer hardware and contains four NVIDIA 9800GX2 graphics cards, each containing two GPUs."
This has dramatically sped up their tomography computations. While not directly related to Blender, this could herald a new era of affordable high-speed rendering? Perhaps this could be useful for the Blender Foundation's next open movie?
Time will tell.
Reported by Sensi