On Twitter: Ashton Kutcher

Sure, Oprah has featured Twitter on her show, and Barbara Walters tweeted on-air from the set of “The View,” but if anything signals Twitter’s explosion into the mainstream, it’s Ashton Kutcher. While the actor often makes entertainment news for tweeting about his annoying neighbors or posting pictures of wife Demi Moore in her underwear, Kutcher made real news nationwide on April 17, 2009, when he became the first twitterer to gain one million followers. It was a close race between Kutcher, CNN Breaking News and Britney Spears, but Kutcher came out on top. It wasn’t all for fun, though: After he won, Kutcher donated 10,000 mosquito bed nets to Malaria No More for World Malaria Day. Since then, Ellen DeGeneres, The New York Times, Jimmy Fallon, the official Twitter page, and lots of others have also reached one million followers.