The New York Times Caucus blog reports (quoting Prime Minister Gordon Brown) that the Queen of England "has awarded an honorary Knighthood for Sir Edward Kennedy." A couple of people have asked: Does this require Congressional approval, under article I, § 9 of the Constitution, "no Person holding any Office of Profit or Trust under [the United States], shall, without the consent of the Congress, accept of any present, Emolument, Office, or Title, of any kind whatever, from any King, Prince, or foreign State"?
I'm no expert on the subject (though I'm not sure whether anyone is), but my tentative thinking is that membership in the Senate or the House is not an "Office of Profit or Trust under [the United States]." Three pieces of evidence for this:
Article II, § 1 provides that "no Senator or Representative, or Person holding an Office of Trust or Profit under the United States, shall be appointed an Elector." This strongly suggests that "Senator or Representative" and "Person holding an Office of Trust or Profit" are two different things.
Article I, § 6, provides that "no Person holding any Office under the United States, shall be a Member of either House during his Continuance in Office." This likewise suggests that "Office under the United States" doesn't include membership in Congress.
There's 1790s Senate precedent for the proposition that a Senator is not a "Civil Officer of the United States" for purpose of impeachment, though the question is not free of controversy.
Note that the situation with Alcee Hastings, an impeached and removed federal judge who became a Representative, doesn't shed light on the subject. Article I, § 3 does allow the Senate to include "disqualification to hold and enjoy any Office of honor, Trust or Profit under the United States" as part of the "Judgment in Cases of Impeachment"; the Hastings situation might thus have tested whether membership in Congress is an "Office of honor, Trust or Profit under the United States" -- but it didn't, because the Senate didn't include such a disqualification within its judgment (a decision that was for the Senate to make).
If any of you have more information on this, please do pass it along, since this post is the result of only a bit of quick research on my part.