The long-standing popularity of "word of the day" web sites and emails has been merged with Twitter to create Artwiculate, a Twitter-based word game that might passively expand your vocabulary while you're taking part in social interruptions.
To play you simply use the word of the day in a tweet. You don't need to use a hash tag or anything special to acknowledge its use. If the word of the day appears in a message on the Twitter network, Atwiculate will pick it up and throw it onto the front page of the site for other Artwiculate users to vote on. At the end of the day, the top 50 uses of the word are shown on the Artwiculate main page.
You could, of course, follow @artwiculate and receive the new word every day without playing along, but what fun would that be?