The scarlet A is the symbol of The Out Campaign, started by Prof. Richard Dawkins. Dawkins is a scientist, author, champion of Darwinian theory and very public proponent of atheism. If you ever need a push to reaffirm your atheist leanings, just read "The God Delusion" or watch "The Root of All Evil?" on YouTube. This is a man who can articulate what most atheists are thinking with alarming precision. By posting the scarlet A, Coming Out of the Covenant will appear on his blogroll! Make sure you visit richarddawkins.net and join the Out Campaign.
Do not feel like you are alone in this process. Coming out is hard, so share your experience to help others. Stand up for reason, science, and logic against unquestioning superstition!