Is a self-balancing electric scooter on your gift list? "They are this year's must-have holiday item, coveted by children and adults alike," The New York Times reports. The gee-whiz recreational novelty with flashy lights is a motorized board that’s also called a Swagway, hoverboard or gyroboard transporter. Prices start around $300, although buyers of the cheapest kinds say they don't last long.

The most popular type, able to reach 12 miles per hour, is a two-wheel model that's navigated by shifting body weight. The OneWheel brand, with a top speed of 15 mph and $1,500 cost, has a huge motorized wheel in the middle. Other brands include Swagway ($400 and up), Hovertrax ($1,500) and IO Hawk ($1,800; see video below.)

Justin Bieber, Lily Allen, Jamie Foxx, John Legend, basketball pro J.R. Smith and rapper Wiz Khalifa are among stars shown riding the two-wheelers that run on batteries. But the technology is so new that there are questions about safety and street use. Few stores sell them because of lawsuit concerns, so most are sold online and promoted with celebrity videos on social media. New York City bans them as unregistered motor vehicles. Riders on streets, sidewalks or parks there can be fined up to $500. London also bars their use on public streets or roads. In California, on the other hand, a law taking effect Jan. 1 allow electric board riders in bike lanes and paths if they're at least 15 years old.

Merchant says: "We're selling a few a day. We thought our main market would be kids, but we've got teens, people in the 40s, even 50s. It's definitely a hot item for Christmas." -- Andreas Rodriguez, Miami Hoverboard Rental

Teen says: "They are very cool. I know a lot of kids want them for Christmas." – Charlie Johnson, 16, of Mill Valley, Calif.

Rapper says: "I stand for our generation, and our generation is gonna be riding hoverboards." – Wiz Khalifa, stopped by police while riding in Los Angeles International Airport