Vincent Gerkens' about his clever solar window concept.
From the moment the sun comes out, you'll be able to extract its powers by opening up the blinds and letting the rays power up the battery cell located on the top of the Venetian blinds. As the sun sets, you'll have the ability to raise them to create a single light source for reading or illuminating your living room without having to use up any extra power whatsoever.
For the curious, you can check out the technology behind the magic over here. Otherwise, you can join us in crossing our fingers and hope this one concept actually manages to go into production (at least on a small scale) so that we can all enjoy some delightful lighting from our windows 24 hours a day.