Bombadil is Sauron?
Ben McC.

Bombadil is NOT Sauron. In Fellowship of the Ring at the council of Elrond, Gandalf referes to Bombadil as "oldest and fatherless" [man], and also as "first"[man] to be part of Middle Earth. (pg 318-319)

In the Silmarillion, Sauron is reffered to as "lieutenant of Melkor" (First big bad dude in Middle Earth) and as cammander of the stronghold of Angband. (pg 47)

Furthermore, Bombadil was never known to be in any way associated with evil.  Perhaps the confusion would come from the fact that the one ring didn't have any power over Bombadil.