From MSNBC:
Three figure-eight knots tied into strings may be the first word from the ancient Inca in centuries. While the Incan empire left nothing that would be considered writing by today’s standards, it did produce knotted strings in various colors and arrangements that have long puzzled historians and anthropologists. Many of these strings have turned out to be a type of accounting system, but interpreting them has been complex. The findings are reported in Friday’s issue of the journal Science.
More here.