A hard shell that unfolds like oragami will fit in a single Starship payload but expand to over 250k cubic meters of space (which seems impossible, that’s like 10 olympic pools) and offers practical solutions for many of the common engineering challenges with building long-term human habitations in orbit.
It’s cool to see concepts like this, even if I don’t expect anything like it to happen anytime soon.
Another one that comes to mind is ThinkOrbital’s spherical station made from welding together rigid panels like a soccer ball.