If people living nearby sea side face problem of acute shortage of drking water, what they should do is to collect sea water and boil it for long time to collect the vapour in a big basin for drinking.
Desalinization is a very costly process. Middle eastern countries which are rich, can afford to go in for desalinization. But for a developing country like ours, with such a vast population it is not economically viable. Moreover in a country where fuel is very expensive, common people will not be able to meet the cost involved in vaporizing the sea water and distilling it for daily consumption.