According to one reporter today at the White House, the answer is yes:
John, go ahead.
QUESTION: Scott, on March the 30th, I believe, last Thursday, Mr. Libby was spotted at the White House Mess. It just seems unusual that he would be coming back to the White House in this situation. Any ideas why he --
Scott McClellan: I don't know anything about that. I don't think so.
QUESTION: You don't think what?
Scott McClellan: I don't think he was here.
QUESTION: What would you do if I --
Scott McClellan: You spotted him?
QUESTION: I have a pretty good source I trust that did.
Scott McClellan: I'll check into it, John, but I don't think that's --
QUESTION: Alan Greenspan was here Thursday, March the 30th.
Scott McClellan: I don't think so, but I'll check. I'll check. I wasn't camped out at the Mess.