I found the VisionTek HD 4670 X2 when I was looking for something interesting to post about. As far as I know, VisionTek is the only one making a 4670 X2 so I wanted to bring it to your attention. It features two HD 4670 GPUs, 2GB of GDDR3 and 4 DL-DVI ports. Unfortunatley the price for this unique card is over three times as high as the regular HD 4670s.
Here is the best and only picture that I could find: