Oprah embraces Twitter: In April 2009, Twitter got perhaps its biggest celebrity nod. Not a tech-industry type, or someone popular with the kids. Twitter snagged Oprah Winfrey, the TV luminary and gatekeeper to a brand new audience for the social website. Twitter cofounder Evan Williams joined Winfrey on her Friday talk show and walked millions of viewers through the process. Oprah’s first message? 'HI TWITTERS. THANK YOU FOR A WARM WELCOME. FEELING REALLY 21st CENTURY.'