This is from a series I did experimenting with an LED and long exposures; the rest can be seen here: http://www.pbase.com/robotography/light

Basically set up a "black box" in the laundry/utility room, where there are no windows and all ambient light sources can blocked out, then shot a variety of light streaks by hand-holding an LED flashlight. I'd wave the light around for the first 3-6 secondes then let the exposure run in complete darkness for 12-15 seconds more. There are others like better, technically, but this one just seems to fit the challenge perfectly (and playfully).