It's recently popped up on Joanne's blog as well as Macallister Stone's - I want to help spread it further. You can read more about the pledge and her reasons for starting it on her website.
Here's a teensy excerpt (teensy because I want you to go to her site)
My brother is the coolest person I know. He's nice to everybody, and he can always make me laugh, even if I'm feeling down. It hurts us when people use words like "retard" and "retarded" in the wrong way, because it makes him feel like they think he's stupid. He had to work very hard-- harder than most people-- to learn how to read, write, play the piano, and use the computer. He has graduated from high school and works at a nursing home. He deserves to be respected, not insulted.
A dear, longtime friend has a brother with Down Syndrome. I believe she feels much the same way about him and hurts like Jenna hurts when people toss cruel words about without thinking. For her, and for Jenna, I signed the pledge and I hope you'll consider doing the same. Thanks.
Jenna Glatzer, Absolute Write, dawno,