As I was sitting waiting to meet with a client, I decided to clean off my desktop and came across the following banner.
Almost every week on Freethought Radio (a podcast from the Freedom From Religion Foundation, http://www.ffrf.org/), you get to hear a quote from Mark Twain - one that I think is really characteristic of belief. As part of their advertising campaign (like the http://www.atheistbus.ca/, etc.), they have a number of banners and this one was saved on my desktop.
They have a number of others that you can view/download at their site ffrf.org.