I've been collecting examples of the "hold a sign" meme in flickr and by way of Erin Stojan of RE-AMP I found this example from the American Rights at Work. The Flickr stream is here. Unfortunately, most of the photos are under an "All Rights Reserved" copyright which can be a barrier to spreading them because you have to ask permission. I asked permission and also suggested they switch the license. It's cool to see these in flickr, an even cooler in Second Life - like the Avatars Against War.