Starting today, Twitter is rolling out its newest feature for web users. Real-time notifications might arrive to you today, or sometime in the next few weeks. What it does is live in a corner of your browser as a pop-up box that will alert you of your notifications such as replies, retweets and mentions. Thankfully, notifications can be disabled just as easily. This one's for those who are just too popular and receive a beep every second (nope, I don't receive any).