The Meta was a large cone placed at either end of the Roman circus maximus, around which chariots would make their turns. As every chariot headed in the same direction, no signal was deemed necessary. I'm not kidding, DesmondMorris stole it from the Roman chariot races. Check it out in any good dictionary - the OED preferably. Look, here's a picture: http://www.ukans.edu/history/index/europe/ancient_rome/E/Gazetteer/Places/Europe/Italy/Lazio/Roma/Rome/Meta_Sudans/home.html
"MetaSignal" is a term from the DesmondMorris book Manwatching. If, for example, you meet an old friend, your emotions rush up and, to safely but effectively demonstrate this, you attack them, but with an irrepressible grin on your face, so they know it's a meta and not a real attack.
Translating metasignals to our new epistemological era required us to invent the winky. ;-)
Well then why doesn't someone start a WinkyWinkyWeb, in which the winky is the context and not the punctuation? You mean besides GreenCheese?
MetaPhorist, n.: someone who can't see the trees for the wood.