Robyn:
I guess that if we were to start throwing labels around then you would be "agnostic", yes?
As you know, I'm an atheist, because I have a lack of belief in God. This is different from believing that God doesn't exist. The position is that, until there is convincing evidence that cannot be explained any other way than by the existence of God, I will by default lack belief in the existence of such an entity.
See, the trouble with saying that we should not dismiss anything we don't know for sure leaves everything open. There is very little, maybe even nothing, that we know for absolute sure, therefore arguments can be made for anything.
Take for instance Funky D's example of Santa Claus. How can we know for sure that Santa doesn't exist? Have we explored the entire universe? Is Santa beyond our comprehension? We may think that we have explained how presents get under the tree, but is the Grinch blinding our eyes? You can see that someone who really wanted to believe in Santa could make the exact same arguments as those who believe in God, and those arguments would have just as much validity.
This is why we lack belief in Santa, because a) there is no convincing evidence for his existence, and b) the stories and myths that purport his existence have been demonstrated to be extremely implausible, and have much more plausible alternatives.
As an atheist, I apply these same principles to God.
Expatbrit