http://www.businessinsider.com/twitter-raising-money-at-1-billion-valuation-2009-9# Dan Frommer | Sep. 16, 2009, 4:20 PM | 1,863 | 11 Tags: Startups, Online, Twitter, Funding Huge: Twitter will raise around $50 million at a $1 billion valuation, TechCrunch's...