As Twitter becomes more popular, it becomes even more important to be able to separate the wheat from the chaff.
Google Reader has just announced a great new feature called Friend Trend, which enables you to see how frequently your friends share posts and more importantly, how often you read them (see image below). You can use this information to tweak your info-grazing habits.
This would be a really great feature for Twitter, visit would enable you to unfollow the people who posted the most content you were least interested in. It only applies to Tweets with embedded URLs, of course, but in my experience that is a large proportion of them. And it would probably need to be implemented by Twitter itself as a cross platfor feature, otherwise anyone who uses more than one interface or whose contacts use more than one URL shortener would get inconsitent results.
Come on Twitter - what do you say?