When deciding which questions to show on the home page, could Stack Overflow take into account the tags I've already responded to?
Say I've asked or responded to 30 questions with the Java tag, 20 with the design-patterns tag, and only one or two with the C++ tag. It seems likely that Java and design patterns are two subjects that I'm especially interested in, or knowledgeable about. So Stack Overflow should show me more questions on those topics, and only a few C++ questions.
I know I can enter "interesting" or "ignored" tags in the prefs. But this treats all "interesting" tags as equal, rather than weighing them differently depending on my interests. It also requires more work from your users, when the site could use information it already has to make this decision.