This half page arrangement:

Rearrangable to:
[Frame 1]
[Frame 6]
on a full page,
on a quarter page, and
on a third of a page.

Used by many major comic strips, including, illogically (as it was used to make newspaper space flexible), Sluggy Freelance.

Invented by Bill Watterson
eduar09: I got the impression from the tenth anniversary book that he was at the very least claiming credit for it, later having rejected it.