I attached this icon to a couple of comments yesterday, and people have asked about it. I found it at the liberal_icons community. Here's the link to the appropriate post:
http://www.livejournal.com/community/liberal_icons/145662.html
ETA: You apparently can't tell by just seeing this post on your friends list, but it's an animated icon. You really should click on the link or open up the post to see what the whole message is about.