"HI TWITTERS . THANK YOU FOR A WARM WELCOME. FEELING REALLY 21st CENTURY."
There's no better proof that this was Twitter's breakout year than that the Queen of All Media jumped onto the microblogging bandwagon live on her talk show. Though Oprah has sometimes been an infrequent Tweeter since her first Apr. 17 message, she quickly developed a massive fan base (now totaling more than 2.6 million followers) and gave Twitter some much needed mainstream cred.