We all knew it was only a matter of time. Exotic cooling solutions first emerged for the CPU, then the video card, and "stock" exotic cooling is available for RAM. With OCZ's FlexXLC series RAM, the modules come stuck at 1.15GHz and are liquid cooled, with a copper heatsink and built-in pipes to move water or other cooling liquids through them. With OCZ producing only the modules, you'll still need to provide your own pump and radiator system, but the simple design of the modules should make them compatible with just about any water cooling system.
The modules run at a very high stock voltage of 2.35V, require 8-layer PCBs and are supposedly capable of 1.2GHz speeds if properly cooled. They are by no means cheap, coming in at a massive $599 for a 2GB kit. They are rated at PC2-9200, making them some of the fastest modules on the market. They are supposedly available next week. Expensive, but impressive.