Korean designers Je Sung Park and Woo Jung Kwon have developed an invisible umbrella that will keep you dry by repelling rain.  Consisting of a simple plastic stick that creates an artificial wind at the top, the ‘umbrella’ deflects raindrops before they hit you by sucking in air at the bottom. The intensity of this wind-shield can be varied depending on weather condition and number of people sharing the device—the length of the stick is also adjustable.