Handbags are mystical and powerful things. Somehow they seem to be bigger on the inside than they are on the outside - like the Tardis. However, this bodes ill for the fate of your keys, especially when it's dark and you really just want to gain access to your home through the front door. Rosanna Kilfedder, a 24-year-old design student from Brunel University in West London, was all too aware of this problem and went to work on a solution. The result is unique: the Sun Trap. The interior of the Sun Trap handbag is lined with a special electroluminescent (and extremely funky) material powered from a solar cell discreetly integrated into the bag's exterior. Open the bag, and 'hey, presto' on comes the bag's light. This raises the old 'fridge paradox' question - "Is the light always on, or does it only come on when you open the door?" - to a whole new level. We'll never know.