This has to be one of the most useful pieces of furniture I’ve seen in a long while. It’s called the Doc System, and it folds from a sofa into a bunk bed. I’m, of course, being heavily biased because of the recent arrival of my first child. Here’s the deal, my wife and I own a one bedroom apartment in San Francisco. Space is at a premium here, so I’ve been search for just such a piece. Now would I really use a convertible modern piece of furniture like this? It depends upon how lazy you are. I’m lazy, so in the end, this piece would just stay a sofa or a bunk bed ninety-nine percent of the time.