Communications Breakthrough (note)

Because you can't see the person who is sending you electronic mail you 
are sometimes uncertain whether they are serious or joking.  Recently, 
Scott Fahlman at CMU devised a scheme for annotating one's messages to 
overcome this problem.  If you turn your head sideways to look at the 
three characters :-) they look sort of like a smiling face.  Thus, if 
someone sends you a message that says "Have you stopped beating your 
wife? :-) " you know they are joking.  If they say "I need to talk to 
you :-( ", be prepared for trouble.

Since Scott's original proposal, many further symbols have been proposed 
here:
 :-)     humor.
 :->     humor variation.
 %-}     humor variation.
 :-(     sad.
 :-<     sad variation.
 %-{     sad variation.
 :_)     tongue in cheek
 :-!     foot in mouth
 <:-)    for dumb questions.

 (:-)    for messages dealing with bicycle helmets.
 (8-)    for messages dealing with owls.
 d:-)    for messages dealing with baseball.
 d :-o   hats off to your great idea
 q:-)    for those who wear their caps backwards.
 @=      for messages dealing with nuclear war.
 o>-<|=  for messages of interest only to women.
 ~=      a candle, to annotate flaming messages.
 oo      for somebody's head-lights are on messages.
 ;-)     say no more, nudge nudge.
 :-$     put your money where your mouth is
 >:->    leer
 ;-}     leer? (terminal dependent)
 |-<>    kissy face
 :-|     man playing an harmonica
 O:-)    for those innocent souls
 [:|]    from a robot (or other appropriate AI project)
 :>)     from someone with a big nose
 :<|     from someone who attends an Ivy League school
 :%)%    from someone with acne
 =:-)    from a hosehead
 :-(*)   from someone who is about to vomit
 :-)8    from someone who is well dressed
 8:-)    from a little girl
 :-)-{8  from a big girl
 #-)     from someone who partied all night
 %-\     from someone hungover
 :-*     from someone who just ate a sour pickle
 -:-)    from someone who sports a mohawk and admires Mr. T
 :-'|    from someone who has a cold
 :-)'    from somone who tends to drool
 ':-)    from someone who accidentally shaved off one of his eyebrows

 8:]     from a gorilla

 (:)-)   from someone wearing scuba mask

 P-)     from someone getting fresh
 |-)     from someone who is falling asleep
 .-)     from someone with one eye
 :=)     from someone with two noses
 :-D     from someone who talks too much

Miscellaneous:

 (-:|:-) Siamese twins
 :~/     Really mixed up
         the invisible man
 {:\/    sounds like a duck
 .\/     duck variation
 :-0
 |:-O
 %+{     from the loser of a fight

   ___
  /   \
 | RIP |
 |_____|    from someone who is dead
 -------

So you see, bit-map displays are really quite unnecessary :->