Today we’re beginning to introduce a new account feature called mute to people who use our iPhone and Android apps and twitter.com. Mute gives you even more control over the content you see on Twitter by letting you remove a user’s content from key parts of your Twitter experience.
In the same way you can turn on device notifications so you never miss a Tweet from your favorite users, you can now mute users you’d like to hear from less. Muting a user on Twitter means their Tweets and Retweets will no longer be visible in your home timeline, and you will no longer receive push or SMS notifications from that user.Twitter Confirms "Mute" Feature Coming To Accounts [blog.twitter.com]
In the coming weeks, we will roll out the mute feature to everyone.