Five years after founder Jack Dorsey unleashed the first tweet ever - "inviting coworkers," is all it said - Twitter now racks up an estimated 1 billion updates a week. "Five years after its inception, Twitter is now serving up an average of 140 million tweets per day, up from 50 million per day at this time last year," reports Tech Chronicles. "And that adds up to nearly 1 billion tweets each week."

Moreover, an average of 8 percent of people in the U.S. use the San Francisco-based social media company. "Currently, an average of 460,000 Twitter accounts are created every day, while the number of Twitter mobile users has spiked 182 percent year-on-year," Macworld notes. "Despite that growth, Twitter seems to have a lot of room for expanding its user base. In December, The Pew Internet & American Life Project reported that 8 percent of U.S. residents use Twitter."

Speaking of first Twitter updates, what was yours?