I'm trying the "digg for tweets" thing (http://laughlitm.us), its hard to gain traction because its hard to get a viral loop going without needlessly injecting the site into retweets. I am happy with how people can submit though.
Another interesting idea, would be for submitters to authenticate with such a site, and have it check their "retweets_of_me" "retweeted_by_me" and "retweeted_to_me" aiming to surface what's important.
Tweetmeme has a comedy channel, I wonder how they get their tweets. http://tweetmeme.com/category/comedy - but the tweet is not initially shown, only the link and its extracted content.
Is there a twitter site aimed at crafting the best possible lists in certain categories?
I would assume tweetmeme flag comedian feeds and counts retweet links.
I believe there are list sites, but the focus is on the feed rather than the tweet.