Trivia: The coordinates of the note lead to Reverend Thomas J. Williams Park in Cambridge, MA, USA. The time on the note, September 23, 2007, was about six months after the publishing of this comic. One hundred eighty-one days, to be exact.
Notably, several hundred xkcd fans met up at that very time and place. Randall also visited the meetup, and was recorded as saying "Maybe wanting something does make it real."
Link to article: https://web.archive.org/web/20160605010651/http://thephoenix.com/boston/news/48208-wisdom-of-crowds/
