When is recusal appropriate?

When should a judge recuse himself or herself from a case? I'm afraid we have some confusion on the subject after a five day long hunting trip shared by a Supreme Court Justice and The Vice President, who is a party to a case that will appear before the Court. Findlaw has an thought provoking article on the subject: Why Justice Scalia Is Wrong To Refuse to Recuse Himself From a Case Involving Dick Cheney and His Energy Task Force