Towels have long been thought of as nothing more than utilitarian objects that everybody has, but about which nobody really thinks twice. Douglas Adams challenged this when The Hitchhiker's Guide to the Galaxy attained cult status in the 1980s.
He described his characters travelling around his universe, often as hitchhikers, finding that towels were the most "massively useful" objects they could carry. The fictitious time/space traveller and Guide Researcher Ford Prefect uses the idiom "a guy who always knows where his towel is" to mean someone generally alert and aware, someone who in 1960s Earth slang might have called "with it". In Adams' universe a hitchhiker who carries a towel can always find a ride because if someone is carrying a towel it is assumed (however illogically) that they also have a toothbrush, a bathroom kit, shower shoes, hair nets, maps, a toolbox, tickets to the opera, finely lapped silicone wafers, a set of encyclopedias, an astonishing array of credit cards, travellers checks etc.
For this reason hitchhikers were directed by the Guide to always carry a towel to maintain the appearance that they would make a good guest. In addition a towel can be used as a hammock, a blanket, a cape. The corners of the towel can be soaked in vitamins, and useful bits of wire can be woven into the towel. The corners of a towel can also be tied together to make a bag. If wet, the towel can even be used in mele combat. Fans of Adams' books have seized on this idea, and towels are now considered a symbol of one's devotion to the Hitchhiker books, radio series, TV series, website, etc.
