FriendFeed: "Does one of your friends Twitter way too often? Is the long discussion about bacon-flavored cookies getting old? Now you can easily hide individual services from people you are subscribed to, mute individual discussions, and a whole lot more by clicking the 'Options' link under an entry in your feed"
Perfect! One less copy of the tweet. FriendFeed is quickly becoming the best at the morass of lifestream aggregators, comment anywhere weirdnesses, and it'll even toss stuff into your feed with a bookmarklet.
ashton @ FriendFeed