From Danish office furniture company Holmris comes the XTable, designed by KiBiSi. The height-adjustable desk is powered not by a motor, but manually, via elbow grease and a handcrank:
XTable is a piece of office machinery that accommodates multiple working positions and daily reshuffling. XTable uses manual kinetic power instead of electricity for height adjustments—saves energy and keeps users active. All technical features are constructively integrated in the table top. It uses a century old principle known from carjacks, ironing boards and other iconic tools.
This one's fresh off the presses and not yet up on Holmris' website; they launched the XTable just two days ago. While the European and Scandinavian markets will surely be targeted, there's no word as to overseas availability. Hopefully they'll make their way stateside—I'd get one just so I could force an intern to satisfy my every work-height whim.