If we are very honest with ourselves, we've all been guilty of this as some point.  Using the word "Retard" or "Retarded" to describe someone or something we think is stupid or dumb.  Its become a word so commonly used by people in our country that they forget its derogatory and insulting.  Originally, Mental Retardation was a term recognized by the American Medical Association, but since then the AMA as decided to stop using it due to the resulting derogatory use.

High School students in Plymouth, Michigan have joined the national campaign "R-Word: Spread the word to end the word".  This local interest in the campaign was started by senior Alex Felts who was called retarded by a fellow student because she participates in special education due to her dyslexia.  In a society where we encourage people to not use derogatory terms for African-Americans or Homosexuals, for example, ending the use of the "R-Word" is only natural and respectful to everyone.

You can learn more at the R-Word campaign's official website.