It is amazing to see how many uses LED lights can have! You can find the flashing LED shoelace in several colors and assort it with your sports shoes. There is the blue, red and green LED shoelace, each powered by one CR2032 battery.
LED shoelaces have three lighting modes – static, fast flash and show flash – and you can turn the light on or off when you want. You can buy one for $11 from Gadget4all.