Every year the New Oxford American Dictionary chooses a word of the year.
This year's word is: unfriend, which is "to remove someone as a ‘friend’ on a social networking site such as Facebook."
There's a load of Twitter one's in there too, such as tweeps, tweetup, twitterati, twitterature, twitterverse/sphere, retweet, twibe, tweetaholic and twittermob.
Oh yes, there was also hot contender: zombie bank: "a financial institution whose liabilities are greater than its
assets, but which continues to operate because of government support."