Elise Co has designed a very cool rain jacket that lights up when rain hits it. From ABC Science Online:
It's coated with PVC and has water sensors on its back and left sleeve.
The sensors are wired via interior electronics to electroluminescent panels on the front of the jacket.
When water hits one of the sensors, the corresponding lamp lights up on the front, creating a flickering pattern of illumination that mirrors the rhythm of rainfall, says Co.
Unfortunately the jackets she's created so far are just prototypes but Co believes they could be mass produced.