Puzzle In xkcd Book Finally Cracked
An anonymous reader writes "After a little over five months of pondering, xkcd fans have cracked a puzzle hidden inside Randall Munroe's recent book xkcd: volume 0. Here is the start of the thread on the xkcd forums; and here is the post revealing the final message (a latitude and longitude plus a date and time)."
XKCD forums are full of auspies. I bet they could crack CAST-128 if you gave them enough time.