Three good posts on what Shakespeare deniers believe:

One, two, and three.

Doing a bit of research on the Austrian State Treaty of 1955, I just came across the transcript of one of President Truman's press conferences, and it's surprisingly funny; Truman, obviously slightly deaf (or perhaps just suffering from poor acoustics), but entirely relaxed about just saying "I can't answer that question", "I have no comment", or "I am not making any statement this morning". Some particular jewels:

Q. Mr. President, I never know how to spell anybody's name. Walter J. Donnelly, how does he spell it?

THE PRESIDENT. Well, I will spell it for you--D-o-n-n-e-l-l-y. You know how to spell "Walter," don't you?

On correspondence with congressmen:

Q: I understand that you recently received a letter from Congressman Cole of Kansas, relative to an RFC loan to Lustron, calling your attention to that. I wonder if you have any comment?

THE PRESIDENT. I have received no such letter. It is customary for Congressmen, when they are running for office, to write letters to the President and give them to the press long before he ever receives them.

And finally, showing a sensible attitude about delegating responsibilities:

Q. Mr. President, will the Secretary of State go to New York to attend the General Assembly meeting?

THE PRESIDENT. I have an idea that the Secretary of State will be there on occasion, if it is necessary. He is not a delegate necessarily, but he is always welcome if he wants to go there. He has my permission to go, if he wants to.

It's particularly interesting to compare the crisp style of Truman's delivery with the incumbent. Though to be honest I think it's as much as anything a change in the habits of public presentation over the last fifty years; I'm sure Clinton's press conferences, if I could be bothered to find the transcripts, would have a much stronger resemblance to Bush's than Truman's in style.

My only personal encounter with this kind of thing was at the time of President Clinton's visit to Belfast in November 1995. I was one of the 2,000 or so invited to the audience for his morning speech at Mackie's, and then was outside the City Hall for his turning on the Christmas lights that evening. I'll always remember his historic words:

I got a letter from 13-year-old Ryan from Belfast. Now, Ryan, if you're out in the crowd tonight, here's the answer to your question. No, as far as I know, an alien spacecraft did not crash in Roswell, New Mexico, in 1947. And, Ryan, if the United States Air Force did recover alien bodies, they didn't tell me about it, either, and I want to know.