Here are some simple and neat concepts from South Korean design collective Monocomplex:
The Free Form Ruler is a measuring device that works like a pencil. The simple idea is that you'd drag the sensor tip along whatever curve or line you need the length of and the numbers are displayed via LED. Rotating the dial lets you choose the unit of measurement or reset it.
The Clip USB is a flash drive that you'll always have on hand and hopefully be less likely to lose, as it clips to your clothing.
The 2Face is a pair of eyeglasses whose color can quickly be changed by "flipping" the frames.