 Vivian Blick - who was one of the team for the revolutionary wind-up radio Freeplay, invented by Trevor Baylis - has a thing about renewable energy devices: his latest, the H2O shower radio (? 34.99, tangogroup.net) harnesses the flow of water in your shower. "The British public loves two things: a shower and a radio," Blick, 48, says confidently. "They want these two things together. Hundreds of thousands of shower radios are sold each year, but the batteries corrode - and although these radios could be salvaged, more than half are chucked into landfill." He wondered why we shower-radio obsessives didn't just use the energy from the flowing water to power our devices. He built a crude prototype, spending two years to get a shower-friendly shape.  But hang on a minute - one of the first rules of eco living is that showers should be brief, thus saving water and the electricity required to heat the water and pump it through the system. Doesn't a radio encourage people to spend eons in the shower? "Exactly," says Blick. "Which is why my second prototype incorporated a shower timer that fits in line with the shower head."  The third - ready next year - will be the energy-saving model. Not only will it harness the flow of the water to power the device, but it incorporates a small LCD screen that tells you in cold, hard currency how much you are spending on your shower. This, he has found, tends to be motivating, even for hot-water addicts. "I just love the idea of grabbing something for free," says Blick, "whether it be solar or wind-up. and I hate planned obsolescence in consumer goods. My message is to get yourself an H2O-powered radio and keep it forever."  PHOTOGRaPH aNDY HaLL