ResourceShelf points to an interesting Vivisimo paper where they discuss information overload and solutions for "ignoring information more knowingly." The Vivisimo solution is to show clusters of search results, allowing you quickly to see what information is available and pick what to explore and what to ignore.
But I'm not sure I agree this is the main problem in information overload. Do you really care about what you've ignored? Or do you just want to be confident that you've seen the most relevant information? The success of the "I'm Feeling Lucky" button on Google (which takes you directly to the first search result) argues that prioritization and relevance is key. Is ignorance about irrelevant information a real issue?