This effect works best at night or in low light.
1)Set your camera to a very low shutter speed (10 or lower).
2)Make sure you have the flash on as well.
3)Position the camera so it is slightly off-centered on whatever colored light you are using. ( In these pictures, I used the light from restaurants and traffic lights (street scene)
4)Press the shutter button and pan (move) the camera smoothly and quickly across and past the light you are using.
5) Admire the amazing results!!! You NEVER get the same pattern twice :)