Speaking of windows, I am absolutely smitten over this room divider. I see old windows at on Craigslist all the time. If you're interested in doing this but can't find matching window sizes, just get whatever you see, paint them all the same color and lay them in a square shape on the floor. Make up for large gaps in between by hanging art or open frames in the middle. Get creative!
I like the found object style. I would take ths idea and make it more random, combining old doors, windows, etc. I would then unify it with one color. There are two very good salvage yards in the dc area.