Barcelona – Amid the megapixels madness of its camera-phone announcements, Samsung has shown us another vision of the future – the Blue Earth. The phone is an environmental champion, made from recycled water bottles and powered by a solar panel on the back.

And that's about all we know. Like the Mona Lisa, the only handset at the Mobile World Congress show is behind glass (which is why we've used the official product shot), and Samsung is being not exactly cagey but a little thrifty with the details. We do know that the phone will have a touch screen and also a distinctly gimmicky pedometer, which measures how far you have walked and then tells you how much CO2 you haved saved by not driving.

This is just annoying, and exactly the sort of thing smug Prius owners would like. It reminds me of the kind of vegan who eats wholemeal pasta – a form of self flagellation designed only to telegraph their pious intentions to us less morally aware mortals.

Still, the intention is good, and the phone has another few eco-tricks up its recycled sleeves. There is an energy saving mode which will lower the backlight levels and switch off Bluetooth – useful when charging via the Sun. That solar panel is also claimed to provide enough juice to keep the phone going indefinitely. For those of us who live in less clear-skied climes (I'm looking at you, Britain) it looks like Samsung will provide a separate charger. Low-powered, of course.

Best of all, it will be a real phone, available in real shops in the second half of this year.