I currently own a Boosted Board and enjoy cruising it around town and while it is already lightweight, lighter is better. The folks at Marbel agree and have come out with what they claim is the lightest electric vehicle to date at just 9.9 lbs. For perspective the Boosted Board weighs 12 lbs.
The Marbel Electric Skateboard focused on trimming weight wherever possible. The deck is a blend of carbon fiber and Kevlar. The Marbel battery is a 165 Wh lithium ion pack that powers a 2,000 W brushless motor. This power to weight combination has a top speed of 20 mph. The board also has an impressive charge time (90 minutes) and range (10 miles).
Another cool feature is the ability to customize the ride to the users liking via a free smartphone application. The Marbel Board comes with the following defaults; low power Starter Mode, energy-saving Eco Mode and Sport Mode. If the defaults don't work for your needs you can customize the top speed and rate of acceleration. Just like Boosted Boards, they are starting off at Kickstarter.