Recently, a friend was at a party and rode an interesting device called 'The Wave'. Born of a skateboard, but modified to make every part fluid, he described it to us. "Good workout", "hard to learn", "looks funky", etc.
After 10 minutes watching videos of it, we hopped over to Amazon and bought a pair. 2 weeks later, we "worked from home" to open a package the moment it arrived. Bike helmets and gloves on, here's a quick review:
The Wave comes with a short bit of printed material, a mis-sized allen wrench and an 8-minute DVD that duplicates the web site content. Trash. Get your own wrench if you want, but it won't change much on the board. Read the booklet, toss the DVD.
In the street, we used the cars along the side to right ourselves and start sliding. Definitely begin facing downhill on a moderate slope. Starting is harder than continuing. Pumping the board to move forward isn't tough to learn. It is quite a work out, however.
Also, be ready to "dump and roll" on the big hills. Carving is smooth and exciting, but it does not slow the board as much as a normal skateboard. You will continuously gain speed until you cry and jump - or until the hill bottoms out.
The Wave is mostly plastic, and rides with a bit of rickety noise from the torsion bar vibrating in its housing. The wheels, casters and bearings are very smooth. The action of riding and turning wears the wheels evenly. While riding, your feet cannot easily leave the board for a "push", so the wiggle-method of propulsion is it, so mastering it is key. One can use kicking legs or a full hula-hoop dance to move forward, but either can climb small inclines.
There are few things to do with the board after riding it. I started spray-painting and sticker-ing mine, but there's little good surface. The board is only slightly heavier than a normal skateboard, and can be carried easily. Small bumps or cracks in the surface aren't much of a problem, and the rider can quickly get over whatever is in range for the wheel diameter.
The torsion bar is fairly weak, even at full crank. This doesn't matter much, since one doesn't rely on it while riding. The friction of the top surface is key, since one needs the feet to stick when the board is twisted. Wet surfaces are a disaster because all of the movement of the wave is in a curve. Wrists and elbows will be the final judge.
Taking The Wave on a packed trail, I was able to roll quite a bit. However, the small diameter wheels forced me onto only the flattest trails (well let's say, it forced me off of all others). Also, the lbs/sq inch of the 2 wheels is higher, demanding a harder surface than a normal skateboard. One spectacular dive was spawned from a trail that suddenly went soft, throwing me sideways at a good clip.
Since you are positioned in "snowboard" stance, rather than facing forward, dumping is not easy. You must jump, turn in the air to face forward, then perform the usual foot-slapping run to slow down. The board slides to the stop quickly, which is better than the traditional runaway skateboard.
Overall, I think this is a great addition to anyone's toybox. You definitely look like an overgrown kid. Be prepared for lots of comments and questions from the curious. Avoid letting kids try it, since they will possibly end up with a mouth full of asphalt and legal hand on your wallet.
Check back soon for helmet cam vids of my adventures on this device.