While originally intended for the deaf and the hard-of-hearing, closed captioning has become something much more. Indeed, CC can dramatically improve your TV watching.

Times when closed-captioning is useful:

• David Duchovny speaks
• British TV
• Background music begins playing, and you don't get the metaphorical importance of it
• Your two-year old sister walks in and exposure to vulgarities may stunt her development
• Various rap, hip-hop, and Backstreet Boys songs
• TV recorders on PC's that search through CC text for keywords
• To see the original dialogue before editing was done (like on The Simpsons)
• So that the black background of the boxes covers up the ever present network logos (that CBS eye gets to me...)
• To better develop one's vocabulary ("alarming" and "disturbing" from the evening news promos)
  And of course:
• The ability to see the future by knowing people's lines before they say them