ODPGuy - 8:51 am on Feb 6, 2002 (gmt 0)

One way to peek inside the Black Box would be to read the patents Google holds or bought from Outride.
Curiously, Google no longer refers to PageRank as patent-pending (they used to). That suggests they either withdrew the application (because they instead chose to make it a trade secret) or it was awarded but assigned to another entity.
AFAIK the Google founders themselves have only one US patent [patft.uspto.gov], but it was pre-Google.