more numbers weirdness
I've never heard of this, but it's pretty interesting.
Numbers stations description:
Numbers stations are shortwave radio stations of uncertain origin that broadcast streams of numbers, words, or phonetic sounds. It is publicly not known with certainty where their signals originate or what purpose they serve. The voices that can be heard on these stations are often those of children, or are mechanically generated.
Numbers stations appear and disappear continuously, although some stick to regular schedules, and their overall activity has increased slightly since the early 1990s. It has been speculated that these stations operate as a simple and foolproof method for government agencies to communicate with spies "in the field", using the transmitted codes as a one-time pad cryptosystem. As evidence, numbers stations have changed details of their broadcasts or produced "special", non-scheduled broadcasts in response to extrordinary political events, such as the Russian constitutional crisis of 1993. Others speculate that some of these stations may be related to illegal drug smuggling operations. Although no broadcaster or government will acknowledge or give a reason for their existence, a 1998 article in London's Daily Telegraph quoted a spokesperson for the Department of Trade and Industry (the government agency that regulates radio broadcasting in the United Kingdom) as saying, "These [numbers stations] are what you suppose they are. People shouldn't be mystified by them. They are not for, shall we say, public consumption."
Errors at the transmission site, radio direction-finding, and a knowledge of shortwave radio propagation have also provided clues to number station locations. For example, the "Atención" station is presumed to be from Cuba, as a supposed error allowed Radio Habana Cuba to be carried on the frequency.
Numbers stations are often given nicknames by enthusiasts. These nicknames often reflect some distinctive element of the station. For example, "Lincolnshire Poacher", one of the best known numbers stations, supposed by many to be run by MI6, plays the first two bars of the folk song of that name before each string of numbers. "Magnetic Fields" plays music from French electronic musician Jean Michel Jarre before and after each set of numbers. The "Atención" station begins its transmission with the Spanish-language phrase "¡Atención! ¡Atención!"
On some stations, tones can be heard in the background. It has been suggested that in such cases the voice may be an aid to tuning to the correct frequency, with the coded message being sent by modulating the tones, perhaps using a technology such as burst transmission.
Even NPR had an article on it...
http://www.npr.org/templates/story/story.php?storyId=3202088
and here's one more...
http://www.straightdope.com/classics/a3_330.html