S4 can be used for writing books and plays: see a transcription of Harry Potter in S4.

S4 can be used for sub-titling films:
(Wait a bit for the video to load, and if the control bar hides the subtitles, try the full-screen mode)

  • karaoke-like
    (a Steven King hit of the seventies,
    possibly the only reggae song you will honestly enjoy)
  • and more serious material
    (a podcast from the Open University)

S4 can be used for to make English-language teaching more efficient: see example here.

And write textbooks, Unit 1 of English 0K!, Social English by the excellent Ken Wilson.
The Chinese version rendered in S4 as a test. The book is published in China and available there for 5.9 RMB, a bargain at third of the price of a hamburger.