So, turns out those little black buttons at the top of the DualShock 4 aren’t the Start and Select buttons. One of those buttons is the Option button, which combines the functionality of Start and Select into one input. The other is the Share button, which stands to completely change the way you spread game content to your buddies.
With a press of this button, you can--on the fly--capture screens or video from the game you’re playing, then upload them online. Judging from the new partnerships with Gaikai, you’ll also be able to upload your finest moments to Facebook, or stream them on Ustream, using this one simple button.