To suspend belief on a subject is to hold off judgment until more information is acquired. This is agnosticism, not atheism. It is an admission that not all information is acquired, thus logically requiring the possibility of the existence of the thing being considered. Agnosticism is the position, in part, that "suspension of belief" is maintained until further information is acquired.
One popular tactic used by religious theists (usually Christians) is to confuse the differences between agnosticism and atheism in order to insist that atheists aren't "really" atheists, but agnostics. There seems to be the hope that by misrepresenting both as two points along a continuum with theism, then atheists can be convinced that they are "closer" to theism than they realized, thus making the entire evangelization effort easier. Evangelization through deception is far too common.
The first error made by this myth is to describe belief as something that one "suspends," as if what a person believes were an act of will that is under their conscious control. Who goes around making decisions about what they will or will not believe? Belief is a consequence of the evidence and arguments we have at hand — when we see a table in a room, we believe there is a table in the room.
We cannot consciously choose to believe that there is no table any more than we can consciously choose to believe that there is an elephant asleep underneath it. Unfortunately, Christianity needs to portray belief as an act of will because otherwise it is impossible for Christians to maintain that we are morally culpable for our disbelief in their god and can thus be legitimately punished. This is not to say that there is no ethics of belief or that we cannot be condemned for believing certain things. It is unreasonable and unjust, however, to condemn a person for not believing something they sincerely see no good evidence for, much less punish them via an eternity in some hell.
Agnosticism is not the suspension of judgment or belief, but the position of not knowing — specifically, not knowing if any gods exist or not. Some may only say that they do not or cannot know if any gods exist; others may go further and maintain that no human does or can know if any gods exist. This may be because (as the myth says) that we lack the necessary information, but for others it may be because we humans are too limited to know such a thing for sure.
Once we understand what agnosticism really is, it should also become clear that agnosticism is not a "third option" between theism and atheism. There is no single continuum between atheism and theism where agnosticism is occupying a middle ground. Theism and atheism are about what a person believes; agnosticism is about what a person claims they do or can know. Belief and knowledge are obviously related, but they aren't the same thing and they answer different questions.
A person who is an agnostic, who does not claim to know for sure if any gods exist, still either has some sort of belief in the existence of some sort of god (believing without knowing for sure is common in many subjects) or lacks a belief in the existence of any gods (not believing without knowing for sure may be more common). Confusing the definitions of atheism and agnosticism is a popular tactic with some religious theists because it allows them to essentially define the territory of debate in their favor. They should not, however, be permitted to misdefine and misrepresent basic categories in this manner.