Here is me in a mirror, in a darkened room, using the Skyliner, one of those LED whirlygigs that are designed to be used at parties or sports events...you program it with one of 10 very short phrases, and then whirl it around, in the dark...due to the way the human eye perceives rapidly-moving things, the LED's are "perceived" as continuous words...even though only one,single letter at a time is actually illuminated...in a dark room, a long shutter speed was used to capture me whirling the thing from as low as I could reach, moving the Skyliner upward, and then at the end of the exposure of about 15 seconds, me firing a NIkon SB-20 flash that I held in the other hand....tripod-mounted Fuji S2, Nikkor 35mm f/2 AF-D lens...
The Skyliner
The web site has a neat animated .gif that shows how one letter at a time can be perceived as a continuous phrase....pretty fun toy...