I'm currently remodeling my loft. Part of the reconfiguration will make much better use of my mezzanine. I want to put my office / workspace in there. (...Lie. I don't want to put my workspace in the bedroom, but it's the only place it'll fit.)
The other day I downloaded SketchUp and started to play. After some maddeningly annoying and frustrating false starts (please tell me it's a bug that there are no keyboard shortcuts assigned to tools by default!), I was able to model my entire mezzanine with a new furniture concept in about 5 hours.
There are things I don't like about this layout: the office area is too busy, and the whole place looks more office than bedroom. So back to the drawing board, but sketchup is a great tool for visualizing my space.
Note: the little wall-mounted horizontal stacks of books represent these invisible book-stacking bookshelves from Chiasso. They mimic the Sapien bookshelves I have downstairs, which currently hold most of my books. PS, I love Chiasso. Check out these vertical stripey tealight holders.