It's been a week full of announcements from Twitter: first the social network debuted a new (arguably Facebook-like) profile design, and today it's officially introducing real-time notifications on the web. We first saw the pop-up alerts in late January, but it appeared to be an experiment visible to just a handful of users. Now -- or, more accurately, "over the coming weeks" -- any time you're logged into Twitter.com, you'll see a notification window alerting you to any replies, retweets or other activities. Conveniently, you'll be able to favorite, retweet and reply to interactions directly from notification windows. Of course, if your Klout score is through the roof and you receive a new notification every second, you'll be happy to know that notifications can be disabled.