I believe there are just too many useful twits that are difficult to trace or follow on twitter. A news aggregation of all twits on twitter designed like Digg where popular news will be the most twitted news or story is the idea. The concept or the basic idea to make this a killer app is in the design. Designing a site an app like that just for twitter will be perfect. I know there are a lot of sites like tweetmeme which is the closest to what I am talking about, but an app with the twist like digg will open a lot of doors for new applications, plugins and buttons to go with it. I am still thinking about a way to make this happen. If you are interested, you can get in touch with me and we can take it from there. I would love to to be a part of your team if you intend to try this alone.