Energy question of the week: How does one turn a T-shirt into a power station?

Whenever the battery in a mobile phone, laptop or MP3 player goes flat, the desperate search for a power socket begins. A power source that everyone can carry with them at all times will provide more independence in the future – their own shirt. That your electronic equipment could ever be recharged by a piece of fabric does sound rather like a fairy tale. But is the 'T-shirt power station' really such an impossibility?