[2] On this day, fans openly carry a towel with them, as described in Adams' The Hitchhiker's Guide to the Galaxy, to demonstrate their appreciation for the books and the author.

You can wrap it around you for warmth as you bound across the cold moons of Jaglan Beta; you can lie on it on the brilliant marble-sanded beaches of Santraginus V, inhaling the heady sea vapours; you can sleep under it beneath the stars which shine so redly on the desert world of Kakrafoon; use it to sail a miniraft down the slow heavy River Moth; wet it for use in hand-to-hand-combat; wrap it round your head to ward off noxious fumes or avoid the gaze of the Ravenous Bugblatter Beast of Traal (such a mind-bogglingly stupid animal, it assumes that if you can't see it, it can't see you — daft as a brush, but very very ravenous); you can wave your towel in emergencies as a distress signal, and of course dry yourself off with it if it still seems to be clean enough.

For some reason, if a strag (strag: non-hitch hiker) discovers that a hitchhiker has his towel with him, he will automatically assume that he is also in possession of a toothbrush, face flannel, soap, tin of biscuits, flask, compass, map, ball of string, gnat spray, wet weather gear, space suit etc., etc.

[6] To promote the group's proposed memorial event, System Toolbox's site director, Chris Campbell, created the towelday.org website.

[citation needed] On 11 March 2013, Google published an official Doodle in recognition of what would have been Douglas Adams’ 61st birthday.

[11] In Canada, Volt, a French/English television show, created a skit in which Towel Day was explained and featured.

[15] In January 2012, The Huffington Post listed Towel Day as one of ten cult literary traditions.

[21] The first SpaceX Falcon Heavy rocket launch used a Tesla Roadster as a test payload, emblazoned with the words "DON'T PANIC!