Just to clarify something:
Agnosticism is NOT “atheism without balls.” It is not a middle ground between believing and not. It is not something you say when you're on the fence and trying to “weigh the arguments” for either side. Agnosticism isn't straddling the fence; it is a valid epistemological position.
An agnostic is someone who is NOT a gnostic*. Being agnostic means you maintain the position that one CANNOT truly know if there is a god or not. One can be an agnostic theist, believing that one cannot know but taking god's existence on faith. One can be an agnostic atheist, believing, too, that one cannot know while not believing in the existence of god.
I've been reading through various religion related posts in blogs and I've noticed that many people make the mistake of equating non-theism or implicit atheism with agnosticism. There is a huge difference.
* The wikipedia entry is kinda muddled, but basically they're people who believed they can know the mind of god. “The Golden Compass” and the sequels have elements of gnosticism in them.