Wind-up media players offer the promise of living free of mains sockets, at least some of the time. Trevor Baylis' Revolution, the second in his Eco Media Player series, lives up to the dream by giving you 45 minutes of music playback for every minute...

Most portable solar chargers look like toys compared to this, the first mainstream charger capable of powering a laptop. While we like solar gadget chargers such as the Solio Magnesium, the Solargorilla really is in a different league.

For...