SOS is the international Morse code distress signal (three dots, three dashes, and three dots, all run together without letter spacing). It became the worldwide standard under the second International Radiotelegraphic Convention, which became effective on July 1, 1908.
Here are some SOS fun facts:
The SOS letters are simply a convenient and distinctive combination and are not an abbreviation, although they have been popularly held to stand for such phrases as "Save Our Ship," "Save Our Souls" or "Send Out Succour".
In 1917 San Francisco aluminium pot salesman Ed Cox, invented a pre-soaped pad with which to clean pots. As a way of introducing himself to potential new customers, Cox made the soap incrusted steel-wool pads as a calling card. These pads quickly became more popular than his pots and pans, so he gave up selling pots and concentrated on manufacturing the cleaning product. They still did not have a name until his wife came up with a solution - she had called them S.O.S pads in her kitchen, meaning "Save Our Saucepans."S.O.S.
by ABBA is the only Top 20 hits in history in which the title of the song and the name of the artist are both palindromes - they spell the same thing forward and backward.