There's a good article on Wired talking about the way in which we brand ourselves, and the persona we choose to reveal. It specifically talks about FB, but really, we do it all the time, everywhere.
Maybe over time enough fragments will compose a complete image of self for others to understand. But then again, which bits to focus on? This or that? These or those? Does this piece go here or there? Or is it that piece that goes with these?