“OMG,” “LOL” and the symbol for “heart” have all been added to the Oxford English Dictionary Online

So what do OMG and LOL mean to the OED? In the electronic realm, they’re merely shorthand for surprise and mirth. In the real-world space — according to the OED’s blog post — “The intention is usually to signal an informal, gossipy mode of expression, and perhaps parody the level of unreflective enthusiasm or overstatement that can sometimes appear in online discourse, while at the same time marking oneself as an ‘insider’ au fait with the forms of expression associated with the latest technology.”

http://mashable.com/2011/03/24/oed-omg-lol/

http://www.telegraph.co.uk/culture/culturenews/8708448/Woot-Retweet-and-sexting-enter-the-dictionary.html