In Response to Matthew McC.
John K.

I would have to say, that Bombadil is most definately not Sauron. Many people think he is a Maiar, likened to a spirit like Gandalf and Sauron, as I did for a while. But Tolkien pretty much dispels these big, powerful assumptions of Bombadil in "The Letters of J.R.R. Tolkien," he states basically that Bombadil is a being that has no desire for power in any way, outside his little woodland realm. The ring has no power over him, he simply has no care for such material things whatsoever, instead of the thought of him having power over the ring to diminish it's effects (as Gandalf basically says in the Council of Elrond that the ring is the thing that has no power over him).

If Bombadil was actually the Dark Lord Sauron in masked form, he would have snatched the ring up for himself the moment he gained possession of it.