I went out with some friends from my photography program the other night to do some experiments with slow shutter speeds and LED light. If you set your camera to the "bulb" setting, the shutter opens - and stays open - until you hit the trigger again for it to close. When the shutter is open for an extended period of time, it continually records whatever is happening in front of the lens, which can make for interesting photographs, especially if your subject is moving. We set out in the dark to the ocean, where we could get the darkest light possible and set up our cameras on tripods. We then turned out the LED lights and began to move them around in front of the lens - many times someone from the group would write behind the person in the photograph. Below is one of my favorites of the series - it was a lot of fun.
And this one is just creepy.
We also tried a similar effect on the neon lights of the Art Deco hotels of Ocean Drive. With a shutter speed of about 10 seconds, I would slowly move the zoom while the shutter was open to get the following effect. I actually really love these!
Below are lights from a restaurant
These are lights from from decorative lights wrapped around a tree trunk. It looks like a flamenco dancer to me.