Project Ara, what would you build?

Just saw the article about Project Ara, the modular phone. Very cool. So many people talking about business strategy, who cares? I want to know what kind of phone would you build? I would want one with an audiophile quality amp and decoder for master recordings. Imagine all the other things you could plug into it and list 'em below. http://www.theverge.com/2013/10/29/5041336/motorola-project-ara-modular-smartphones