Tweetmeme tracks the popular links posted to twitter similar to techmeme does for tech blogs.
Tweetmeme tracks what content is posted to twitter and ranks the content based on how many users are posting or how popular is that among twitter crowd.
It can recognize the content as Blogs, videos, images and audio.
I don’t know how much it is useful for the users, but its fun to watch these type of services. Via Techcrunch
