How do you tell when your mobile phone is running low on power? You check the screen, where there's usually a battery gauge or some kind of power meter. But researchers at Glasgow University have come up with a much cleverer way of doing it.

Instead of looking at the screen, a combination of the speaker and the vibration buzzer can let users 'feel' how much power there is left - apparently it'll feel like it's sloshing about like drink in a carton.

It's a clever idea, and a good proof of concept, but there can't be that much call for this technology, surely? How hard is it to take the phone out and look at the screen?

via New Scientist (link includes video clips)