Do you have a VITA? If you answered yes then it's one of the most useful things for the PS4 as you can use it for remote play. Remote play let's you stream your PS4 to the VITA's screen and continue playing that you can do that quest on Witcher III whilst your loved ones on Christmas day can watch that Eastenders special.
But's not just the VITA you can do remote play as if you got one of Sony's phones or tablet you can stream to that and connect your controller and soon a App will becoming to PC & Mac's to do the same that you will able to play your PS4 in any room.
If you don't want to be sat in the corner on the VITA by yourself but want to be social with your PS4 then theres so many options:
Be it that you can see on the PS4's UI you can see what your friends are playing under what's new and if they have done anything cool with shared screenshots, trophies they've earned for instance and you can as well straight to twitter to show the whole world as well.
That's all cool but the big one is streaming to Twitch, Youtube or Ustream.
That's my stream of Dragon Quest Heroes, if I had a PlayStation Camera, I could have my face showing as well and use that to command the PS4 with my voice.
There's a few other things by setting up the PlaySation App on your phone, you can check the live chat out whilst your playing the game in full screen and if your a big fan of what game your playing you can join a coumminty to talk to like minded people and even set up games with strangers.
But what if your stuck on a game well theres share play which allows you to share a game with someone for 60 minutes, that you can let them take over you game or the time I used it I played Dead or Alive 5 with my mate in versus mode just like it would be on a couch with only me needing the game.
In the future the coolest thing you could do is use one of these..