I agree with Kim, basically. I have no problem with the word "retarded." I have a problem with people always expecting everyone else to be politically correct and overreacting to some things. No matter what you change a term to, someone will use it derogatorily. "Mentally challenged," "developmentally debilitated," or whatever, all get used to refer to someone stupid or weird. Retarded individuals were taught to call themselves "special," and now that term can be used as an insult, too.

Forget about changing words and terms, and if using them as an insult bothers you, don't do it. Just know that others will.