In my opinion, what roller blades are to roller skates, this board (the Shred Sled) is to skate boards.
Not only are the wheels "in-line", the Shred Sled's foot boards are attached by a flexible piece that allows each section to move in different directions. This gives the board more maneuverability, also allowing you to start grooving and moving without pushing off. And it also lets you go uphill!
So the other weekend I had a chance to give my nephew the Shred Sled to try out. He was so excited and decked out in his helmet ... just in case. It was ready to ride out of the box, no assembly required. I read the directions and we started practicing. He would place a foot on each concave deck and we placed it next to a wall so he could learn how to get his balance. He went from needing assistance to stand to riding down the hallway. After that, he went outside to practice and was getting better and better! Here is a picture of him inside practicing.
He hasn't had a chance to ride it again since this day, because his sister poked him in the eye with a feather and scratched his cornea. His family has corneal dystrophy, so his eyes are very sensitive and pretty much he needs darkness and stillness until it heals again. But, I am going to get my sister to send me a video when he gets on the board again.
The Shred Sled is like a combination of snowboarding and skateboarding. The 4-80mm polyurethane wheels and ABEC-5 Bearings are SMOOTHER and STRONGER and rarely need to be replaced. And the concave decks make for better foot control. Plus, the 4 inline wheels offer more control than 2 wheel boards.
Here you can see how to ride a Shred Sled:
This is just such a cool ride and would make an excellent birthday or Christmas gift! They cost $119 on ShredSled.com - and Shipping is FREE! Available colors are red, blue and black.