We're nearly past all this; Monkeyfish sits in a regular chair as often as not. But the Nest chair by Sally Dominguez certainly is cool. And it converts to a lounger, somewhat mitigating its $575(!) price tag.
Or, check out the Calla high chair by Yves Behar (price TBD).
Picked one? Great. Now all you need is a loft apartment in Milan.