NEC and Hitachi have developed a Water cooling technology which will bring the temperature of the hard drive down and the hard drive will function at less then 5db. NEC and Hitachi employs noise absorbing, heat conducting plates and a low-speed radiator fan for this technology to work. According to the companies, the material used in the plates and housing is the most efficient heat conducting material ever. To get this hard drive you will be paying 20,000 more yens in Japan.
You can read more here: Arstechnica