YouTube is already a pretty amazing service, hosting billions of hours of video for free just cos. Now it's getting support for 360 degree video. Yes that's a thing.
Basically it means that you'll have the option to pan around inside a video while its playing. It feels a little bit weird at first but definitely gives you an added element of interactivity. This functionality is currently only on Chrome on desktop and on the YouTube app for Android phones. Check it out here if you're running the right browser.
On mobile, you can do the same thing while moving your phone around as though you're actually in the real location. I'm not so sure about that. 360 degree video doesn't feel all that much like you're actually in the real location (looking up and down is certainly easier in real life) but expect this kind of footage to become much more common in the years to come. That's because it's the kind of content which will benefit users of Virtual Reality headset, and this experience would undoubtedly be more immersive via Oculus Rift or Morpheus.
YouTube's official blog recommends some 360 degree cameras for taking this kind of footage - includingBublcam, Giroptic’s 360cam, IC Real Tech’s Allie, Kodak’s SP360 and RICOH THETA - and take note that there's some extra info you have to add to the outputted video before it will display like this once uploaded.
360 videos will also be coming to YouTube on iOS devices soon.