Well, I must say I'm disappointed. When I saw the thread title I thought we were going to get the post-McGrathian, and very pertinent, question, "Are atheists really atheists or are they all really just agnostic?" Now that might have made a much better thread!

Not keen on this: I would venture to say that an atheist rejects theism and an agnostic sees no clear evidence one way or the other.

I don't think a genuine atheist has rejected anything as such. It's more a matter of weighing up evidence for the existence of God, finding it severely wanting and, as a result, living one's life in spite of all the brouhaha surrounding him. Oh, and having a damn fine argument with believers every now and then! I don't find "agnostic" a very useful term. It covers far too wide a spectrum for a single little word. There are those who can't be bothered, those are are confused by the whole thing, those are don't like to say there's no God out of fear, and the almost-certains, in which category I might include myself and, definitely, Richard Dawkins. "Atheist" is a pithy little word which those of us at our end of the spectrum accept by way of expedience only.

In that regard:

There are many definitions of atheism, but I think the most general one is 'a lack of belief that a deity (or deities) exist'.

The trouble with this is that I'm supposed to lack something (all together now... ;-) ) I certainly take a radically alternative view of the universe to that of believers, that's for sure, but I'm not sure I want to accept that I lack something which they don't. Could be that, by ditching faith, I've gained more than I lost. Who's to say?