I used to describe myself as an agnostic, but now I describe myself as an atheist. What changed was not my faith (or lack of it) but what I understood those words to mean.
I used to think that the meanings were as follows:
Atheism: I believe there is no god.
Agnosticism: I neither believe nor disbelieve in God.
But I know think that the following definitions are more accurate:
Atheism: I do not believe that there is a god.
Agnosticism: I have no opinion about the existence or nonexistence of God.
Specifically, I don't think that there is a god but would rather avoid describing myself as having any sort of "belief" one way or the other, because that word carries some implication of "belief without (or despite) evidence". While it's impossible to ever prove with certainty that there is no god (or indeed to prove with certainty anything other than "I think, therefore I am") I think that there is a great deal of evidence that there is no God. I'll take a look at some of this evidence tomorrow.
There is alot of arguing about definitions. As it is I go with this definition-
agnosticism is about knowledge.
atheism and theism are about belief.
What you are stating for atheism would be strong atheism under this scheme and what you give for agnosticism would be weak atheism.
As it is, a good number of gods are impossible, while others are simply meaningless. If you stretch the meaning large enough you can get things that exist- and probably fall under Clarkes third law.
My currently stated public religious belief is "incomprehensible, verging on vaporous and annoyed"
Take a look at my movie. My webserver is kind of out of commission at the moment.
I tend to describe myself as an Apathist -- it is of no importance to me whatsoever whether God (or any god(s)) exist. Such an existence makes no difference in how I behave towards myself or towards other people. I am capable of managing my own moral behavior.
Probably I also like to describe myself that way because I enjoy the neologism.