Douglas Adams author of Hitchhiker’s Guide to the Galaxy, died May 11, 2001. Two weeks later, fans of his work created Towel Day. According to this article at Wired.com, D. Clyde Williamson made the initial proposal May 14, 2001, in the “Binary Freedom” forum at System Toolbox:
Douglas Adams will be missed by his fans worldwide. So that all his fans everywhere can pay tribute to this genius, I propose that two weeks after his passing (May 25, 2001) be marked as “Towel Day”. All Douglas Adams fans are encouraged to carry a towel with them for the day.
Make sure that the towel is conspicuous — use it as a talking point to encourage those who have never read the Hitchhiker’s Guide to go pick up a copy. Wrap it around your head, use it as a weapon, soak it in nutrients- whatever you want!