emoticon is a term that evolved in internet culture from mailing
list and usenet users.

During the early days, someone [[anyone have more details here?]]
used the ASCII string ''':-)''' to indicate a smile.

Since that time, many emoticons have evolved [[someone want to put
some urls here to emoticon encyclopedias - preferably freely distributable
ones??]]

In recent years, several of the graphical messaging clients have added
a graphical touch - converting ascii strings typed by the users into
some icon.

[Tkchat] recently added this functionality.  Some of the emoticons it supports
includes:

 :-( :^( :(              - cry
 8-( 8^( 8( 8-| 8^| 8|   - growl
 LOL                     - laugh  
                         - mad
 :-o :^o :o :-O :^O :O   - surprise
 :-) :^) :)              - smile
 :-D :^D :D              - big smile
 <:-) <:^) <:)           - dorky smile
 8-) 8^) 8)              - smiley with glasses
                         - smiley with tongue
                         - smirk with glasses
 :-p :^p :p :-P :^P :P   - smiley with tongue, 2
 (: (^: (-:              - upside down
 ;-) ;^) ;)              - wink


There's a few holes in the table above because I was unable to determine
what triggered the icons.