Click / Touch and drag!
Images captured by handholding an iPhone using Google Photo Sphere (from the Street View application), which then automagically stitches the together. This was then emailed from iPhone camera roll to a PC, where the image size reduced, it was then uploaded to website ‘media’, and inserted into post with ‘Add a panorama’ button.
Still a large(ish) image size at 2Mb, this example is set to auto load (see ‘Settings / WP Photo Sphere’ while logged in for options).
Seems to work poorly in Internet Explorer 🙁
Doesn’t go full screen on iOS (Clicking the lower right square takes it to full screen on desktop class browsers).