Will You Be Twitter’s 500 Millionth User? [UPDATED]

Update: Shortly after 1 p.m. ET, Twitter hit 500 million users, according to Twopcharts.com. Naturally, the analyst company is on to the next benchmark — the countdown to 600 million registered users. The estimated time until the next Twitter celebration is only 108 days away. There were an estimated 922,000 users accounted for in the past...