AlyssaS - 4:22 pm on Aug 28, 2010 (gmt 0)
There's a very interesting "top links" list on the right hand side for some searches - I presume these are links in tweets that keep being retweeted, as if you click "all mentions" underneath, it brings up all the tweets it was contained in.
try searching "debt", and you get an economist.com article as the "top link". It comes up on some other searches too. I can see all the twitter spammers going crazy getting their followers to retweet their stuff.