Harry Bertoia's welded wire chair for Knoll is a 1950's modernist classic. It's still in production, and when spring finally decides to stay, I'm guessing they'll be back in the Sculpture Garden at MoMA, just like the good old days. [If by chance they're not--because of some big product placement deal with the Danish government, for example--they're still down the street at Paley Park, 3 East 53rd St).
Anyway, there are/were kid-sized versions at one time, but they're rare finds now. Kid-O in NYC had one, and I see that the Nonchalant Mom, a Rhode Island-based Manhattan refugee is selling three of them on her site for $250 each. They're original white with original orange vinyl seatpads.
Harry Bertoia kids chair, $250 ea. [nonchalantmom.com, via bloggingbaby]