Corsair have just released some new GPU water cooling blocks tailored to NVIDIA's current crop of high-end video cards (GeForce 7800, 7900 GT/GTX, and 7950GT), these blocks designed for Corsair's Nautilus500 external liquid cooling system (and other third party liquid cooling solutions that utilize 3/8" tubing).
Grab Corsair's press release for more info.
The Corsair Nautilus GPU water block is designed to provide maximum cooling for NVIDIA GeForce7800, 7900 GT/GTX and 7950 GT series video cards in both single and SLI configuration. Constructed with a pure solid copper base and RAM cooling pad mounting points design, the Nautilus dual GPU water blocks provide optimum cooling directly on the GPU and the video RAM. This additional cooling allows for significant GPU overclocking. The compact low profile block features a single inlet and outlet for cooling two video cards that reduces the tubing lengths and improves the flow characteristics of the water cooling sub-system.