Ben Sparrow and Joshua Zoshi have come up with an ingenious way to desalinate water using a series of brine solutions of different concentrations, together with a solar-assisted evaporation component.
According to an article in the Economist the best reverse osmosis systems currently consume about 3.7 kWh of electricity to produce 1,000 litres of drinking water, whereas the Canadians' company, Saltworks, claims to be able to produce the same amount of drinking water using less than 1 kWh of electricity.
To develop such a technology in Vancouver, where it rains non-stop and you rarely see the sun. =)
More on this new technology can be found at Cleantech Blog.