Apatheism: The concept that the existence of gods is irrelevant to one's day to day affairs. I mean, if $deity is so huge, he doesn't need me to follow a bunch of obscure, ancient rituals to worship him. Being good to other people is enough to get me through the day feeling good about myself.
Ignosticism: The assertion "God exists" or even the term "god" is cognitively meaningless. Since everyone's conception of god (including atheists') differs, until a coherent definition of "god" can be established, the question of god's existence is unanswerable.
Nontheism: The belief that there is not a ancient white guy with a beard up in the clouds somewhere. It makes no assertions as to whether there is a benevolent or underlying force driving the universe; it applies both to certain kinds of atheism as well as certain religions such as Buddhism.
Indifferentism: Belief that there's some kind of god, but that he doesn't care how you worship as long as you adhere to some kind of faith/are a good person.
Secularism: The tenet that whatever you believe, you should keep your religion and your public life separate, out of respect for those who choose to believe differently than you do. Not actually opposed to freedom of religion; quite the opposite. It's kind of a religious détente to sort of live and let live. You can't push your beliefs on someone else, but consequently, you don't have to worry about them pushing their beliefs on you.
I have no idea if you've spent anywhere near as much time thinking about this as I have. I'd imagine it's part of the "recovering Catholic" mindset. I just thought I'd share because I found it interesting that there were so many ways to distinguish one's religious views (insofar as one might answer the question: "What church do you belong to?" or "What do you believe?"). I know there's a gigantic prejudice in this nation against "atheists" (many people believing it synonymous with anti-theist; someone out to destroy their gods). A-theism itself, from the Greek, means "apart from god/s" or "without god". But I kind of like Apatheism, because that's how I emerged from Catholicism. "Look, 'GOD' doesn't care if I'm in church on Sunday, when I'm kneeling or standing, or whether I've eaten before accepting the Jesus-bread. He's got bigger things to worry about and as long as I'm a good person, I'll have 'heaven' right here on earth in the knowledge my actions bring joy to those around me." That's the conversation I had with my mother. And, in a sense, it's true. I don't want to worship a god who watches my every move, looking to take offense. Having to conform to ridiculous amounts of rules is EXACTLY my idea of hell. I don't think my mother realizes; she still seems to think of hell in terms of fire and brimstone. (I found out that brimstone, by the way, is sulfur. Like, rotten eggs, stink bomb, fartstank-component sulfur. So hell is fire and fart-smell. I guess the Christian devil is just a flatulent old bastard.)