LinkedIn (LNKD), the social network geared to business professionals, said early Wednesday that it has topped 200 million registered users, about 74 million of whom are in the U.S. The U.S. leads in members, followed by 18 million in India and 11 million each for Brazil and U.K. "It's been amazing to see how our members have been able to transform their professional lives through LinkedIn," Deep Nishar, LinkedIn senior vice president, wrote in a