You'd have to be pretty old to be nostalgic about an abacus, but we sure do appreciate the whimsy of this design. Not to mention the tactile pleasure it would bring a young child.
The design is the work of Eva Korae who lives and works in Cyprus and it was shown as part of London Design Week. We don't expect it would be terribly comfortable to actually sit in, but it pleasantly and playfully evokes a simpler time. We're imagining a small abacus used as a seatback on a kid's chair which might have the same effect and still be functional (diy it and let us know!).
You can see more of Korae's imaginative work at on her site, Seks.