Some interesting news came out of Lawrence Livermore Labs recently that applies nnanotechnology to a desalinization process, making sea water safe to drink.
A few articles already exist on this, so I’ll just link to them here.
Lawrence Livermore Press Release: Nanotube membranes offer
possibility of cheaper desalination
Nanotechweb: Carbon nanotube membrane filters fast
WorldChanging: Nanotechnology for Clean Water