Aqua Google

Can't see it happening myself, can't see it being economically viable, but Google has filed a patent for placing server farms on barges in the ocean:

The Google design incorporates the Pelamis Wave Energy Converter units, which use the motion of ocean surface waves to create electricity and can be combined to form "wave farms." The largest existing project uses seven Pelamis units to generate about 5 megawatts of power. Diagrams included with Google's patent application indicate the company plans to combine 40 or more Pelamis units to produce 40 megawatts of power.

The patent documents describe a cooling system based on sea-powered pumps and seawater-to-freshwater heat exchangers.

I mean really, how expensive is land relative to all the other costs of normal data centers. To save a little bit of real estate costs (and real estate is actually an investment most years), you'd have to have cables running to the mainland, with all the extra difficulties of underwater repair/maintainence, plus ferrying staff out there, plus dangers of tropical cyclones....

Dumb idea, but clever none the less.