We first heard about Carlos Arredondo when he set himself on fire after hearing of his son's death in Iraq. Since recovering from the burns, he has been a very outspoken part of the antiwar movement.
Here is a video of him speaking to a group of children. It is kind of long and may make you cry.
At the ANSWER rally and march, he was attacked by a group of Chickenhawks from the Gathering of Eagles. You can read the story at AfterDowningStreet.org.