Retarded. Celebutard. Fucktard.
These words are now part of the popular lexicon, especially on the 'net, and I'm reasonably certain that most people who use them bear no personal malice toward those who are mentally handicapped. But I also doubt that most people who use variations of "'tard" have ever actually known someone who is mentally retarded.
As the mother of an 11-year-old mentally retarded boy, I don't take it personally. As I mentioned in comments on another blog a couple of days ago, I usually "turn a blind ear." When a developmental pediatrician actually spoke the word "retarded" when diagnosing our son a few years ago, we cried a bit, but it confirmed what we already knew in our hearts.
No one chooses to be mentally retarded. In my son's case, his brain damage was one of those freak-of-nature occurrences, a detached placenta that went undetected, and starved his brain and body of oxygen the last several days in utero. If you had asked me when I was pregnant what was the worst thing I could have imagined, it would have been to have a child that was severely retarded. Now that we have one, I realize that there are many outcomes that are far worse. He's happy most of the time, he's physically healthy, he's able to walk and talk and enjoy a good roller coaster ride and basket of fries, and he has an insatiable curiosity about the world and eagerness to learn. He's surpassed his initial prognosis by several thousand degrees, and based on where we started, we truly feel blessed.
It's not worth my energy to open up a can of verbal whupass every time I see someone call something retarded that a word like clumsy or ignorant or foolish or ungainly or inelegant would describe far better. We've evolved to the point where insults based on race, ethnicity or other physical characteristics are frowned upon in most polite company; let's be conscious of extending that consideration to those with cognitive disabilities as well.