Weather forecasting umbrella
An umbrella that provides information about the likelihood of rain so that users can make a simple, informed decision about whether to take the umbrella with them as they leave their home. after retrieving the weather data via a wifi connection, the handle glows more intensely with the increased chance of precipitation.
Good example of putting information where it is needed: Context is content. The environment becomes the interface again.
And some context based energy. Not the sun this time, but the rain: http://www.physorg.com/news120216714.html