If I visit a site X number of times in Y time period, and that site has an RSS feed, ask me if I want to subscribe. It would look something like this:
This should probably be cleaned up a bit and maybe add a button for OK and Cancel and a checkbox to not annoy me about this again. This would help me since I can't seem to remember to subscribe to some sites even though I view them fairly often. Yes, I'm suggesting adding a feature instead of fixing my brain.