Industrial designers Mike Simonian and Pieter Schouten made this skateboard in order to add the flexibility of snowboarding movements to skateboarding:

The Flowlab Skateboard allows you to surf without waves and ride without snow. Years of experimentation resulted in the geometry that allows a device with no moving parts to simulate the fluid motion of snowboarding or surfing on land. The arced axles let you carve to 45 degree angles with no resistance and fluid transitions edge-to-edge.

You can view a technical drawing of the design at the link.

Link via DVICE | Photo: Mike & Maaike