The hydrofoil looks set for a second coming – as a ferry. The boats, which are fitted with skis and electric batteries, literally plane across the top of the water. They're fast, less polluting than traditional passenger craft and could be the perfect marriage between climate-friendly technology and rapid transit needs. Authorities in Sweden and the UK are just about to begin trials. Also, turning trucks into trams – why are Swedish researchers looking to electrify their roads? And the floating, solar vegie-patch – could it boost food production for remote or disadvantaged communities.