Here is a cool design for a light from designer, Shinyoung Ma, the The Pinch EL Light, or Electroluminescence Light.
The light is designed in two parts, a cable with a clip holder and a light that clips onto the cable, once the light is clipped on it lights up.
The idea is that you have different light that you clip on to the cable to change the look and mood of your room, you could choose different color lights, or ones with different graphics.
This is a great idea, very clever yest simple, and it certainly would make things a lot easier when you wanted a new light fitting, unfortunately it is just a concept at the moment, lets hope some manufacturer picks this cool design up.
Yanko Design, via Geeky Stuff, Like Cool