I came across an interesting stock screener/filter recently: Stockpickr.com
Its described by some of the creators as a "MySpace for stock picking" (but I’m not sure if thats a good thing). A better way to think about it is more like Amazon’s recommendation engine. If you put in a stock (or a full watchlist of stocks), the system’s algorithm or colloborative filters will spit out recomendations from hedge funds, mutual funds, and investors like Buffett, Soros, etc. who own similar stocks to yours.
You also can browse through these portfolios (hedge funds, mutual funds, Buffet, Soros, etc.)
James Altucher is involved, and even though we frequently disagree about macro-economics, he has a good history with both hedge funds and online stock analysis.