When you're out at the bar tonight, knock a few back for one of your favorite timesucks on the interweb, which celebrated its fifth birthday today. Twitter, now an indispensable communication tool for millions (which some say is worth billions) launched on July 15, 2006 as Twttr. In those days, the site was a bare-bones service primarily based on text messages sent from your phone. The iconic features that everyone associates with the microblogging site today, like hashtags, @replies and trending topics, were all created spontaneously by Twitter's early users. Good thing they did, too-- the site has grown so fast since that more people signed up just yesterday than in Twitter's entire first 16 months. #ballin