Given current energy costs and up-to-date technology, what is the cost of desalinization of ocean water?

US $0.75 per cubic meter.

A nice 20-minute shower consumes about 150 liters, or about US $0.12 worth of desalinated water.

Keep this in mind next time someone asks you to "be responsible" and "conserve water".

However, it does take some 2.5 - 5 cubic meters of water, rain and all, to produce a quarter pound hamburger.