Was the Obadiah in 1 Kings 18 the same Obadiah who wrote the Book of Obadiah? Pretty straightforward question - In 1 Kings 18, Elijah speaks with a servant of the Lord named Obadiah.  Is that the same guy wrote the book of the same name?
For what it's worth, I once heard a sermon in which the preacher said it was not the same fellow. 

My bible has the following intro to Obadiah:


  Obadiah wrote this shortest book of the Old Testament probably soon
  after 586 B.C. when the armies of Babylon destroyed Jerusalem. During
  this conquest, the people of Edom helped capture fleeing Israelites
  and turn them over to the Babylonians. They even took up residence in
  some Judean villages. This angered the Lord, for the Edomites, as
  descendants of Esau, were related to the Israelites (Gen. 25:21-26,
  30) and therefore should have helped them. Obadiah prophesied that
  Edom would be repaid for mitreating God's people. Within a hundred
  years, Edom was in ruins. Obadiah also asserted that God is sovereign
  over the nations and that the house of Jacob would be restored because
  of God's covenant love for his people.


This would seem to preclude the Obadiahs being the same, as Elijah was well before the Judean exile (he was even before the northern kingdom was overrun).