Houston sign-spinners prepare for world championship in Las Vegas

What we know:

HOUSTON - Human billboards have existed for centuries, but sign spinners have gained attention in the last several years as a performance art designed to get attention for businesses and events.

It's hard, athletic work requiring hours of attention in all kinds of weather. Spinners spend years advancing basic moves to tricks and techniques that are designed to attract the attention of drivers and passers-by. A handful of Houston competitors will be among dozens from across the country, and around the world, for the World Sign Spinning Championship in Las Vegas. Each has worked to perfect a secret collection of tricks to wow the judges, who will looking at technique, execution and style.

What they're saying:

"To me, sign spinning is more of an art; a performance; it's a way of self expression, and that's what I get the most out of it," says sign spinner Jimmel Martin, "When I started experimenting and trying new movements, techniques, and tricks, I started to realize I had an affinity for it and I liked it, a lot."

"Tricks, aside, you're just seeing someone who truly enjoys themselves," says Martin, "I'm trying to make you my best friend for the few seconds that I get to interact with you and, hopefully, I brighten your experience."