“We’re Greenpeace, and we want a fresh green Apple.
Right now, poison Apples full of chemicals (like toxic flame retardants, and polyvinyl chloride) are being sold worldwide. When they’re tossed, they usually end up at the fingertips of children in China, India and other developing-world countries. They dismantle them for parts, and are exposed to a dangerous toxic cocktail that threatens their health and the environment.”
Write to Apple to demand they:

• Remove the worst toxic chemicals from all their products and production lines.
• Offer and promote free “take-back” for all their products everywhere they are sold.

via greenmyapple.
I added this to the form letter part:
“I’ve been a Mac fan for a long time, and I was really disturbed to learn that Apple scored so badly on environmental impact. As much as I’ve loved my Macs, if I have to choose between my green values and my Mac, my green values are going to win.”