The life, work and all-round fantastic wonderfulness of author Douglas Adams is being celebrated across the universe today.
The first Towel Day took place on 25 May, 2001 - two weeks after Adams' death - and now his fans mark the event every year, proudly carrying a towel in his honour and taking part in all sorts of Hitchhiker's Guide To The Galaxy-themed events around the world.
So whether you're walking along Edinburgh's Royal Mile in a dressing gown (and carrying a towel and a cup of tea), taking part in London's Vogon Poetry Slam, going along to the Berlin flashmob, or simply raising a glass in honour of Mr Adams today, we wish you all a very happy Towel Day - and leave you with 10 quotes by the man who taught us all we needed to know about life, the universe and everything. The chief lesson among these being, of course, that you should always know where your towel is.