While it's not quite as immersive as a full virtual reality experience, 360-degree videos and photos are becoming more common (especially on Facebook and YouTube), and now Valve has released a Steam 360 Video Player. It uses adaptive streaming from a company called Pixvana, which should enable playback with just one click on your Rift or Vive headset. According to the FAQ, even if you don't have a headset, it will soon support playback on the desktop with control and navigation by mouse.