The fine people of Cabinet magazine (which I je adore) have just published a book on Presidential Doodles with Basic Books (who do lots of interesting stuff).
You can see some examples at the book’s site; Warren Harding’s are sleek, decobeauties. (Via Austin Kleon.)
Paul Collins apparently did the intro to books. He blogs about it a bit (and the history of doodling as he sees it) over at his lovely little blog:
weekendstubble.blogspot.com
Cheers!