Twitter's Jack Dorsey

A Q& A with Jack Dorsey, the co-founder and CEO of Twitter -- the two-year-old free microblogging site that is racking up high-profile enthusiasts who hail it as both a "hypergrapevine" news resource and an innovative business tool for customer service. The fast-growing communication service is said to have more than 2 million accounts set up for sending and receiving "tweets" -- quick-fire text messages that are limited to just 140 characters. The San Francisco-based Twitter has 24 employees and recently won $15 million in funding. Dorsey, 31, is widely acknowledged as the man behind the Twitter concept. The St. Louis native and New York University computer-science dropout says he is excited about his site's rapid accent, the new Twitter show on CNN, and possible models for monetization -- as even newer communication upstarts nip at his heels.