At my first ever job (my last job) I was a shop girl at an antique store. Among the many old antiques that I loved, I discovered these metamorphic pieces; a bench that turned into a step ladder or a chair that folds down into a bench. They looked like they would be perfect in a library or a sitting room (in my imaginary home in the English countryside).
From Treehugger.com this retro futon folds into a wooden coffee table.
From Treehugger.com I found this crib and changing table that doubles as a day bed and desk! I think it still looks like a crib but......