Design group KiBiSi (the one behind Aiaiai TMA-1 headphones) recently presented Holmris X-Table. The "X" shape of its legs is a main solution for the instant adjustment of the work surface height what everyone try to compensate with unhealthy gas-patron office chairs.

You can buy one on http://www.holmrisonline.dk/haeve-saenke-borde/X-TABLE