Thanks to Rex Hammock for the pointer to Safari Reader, a new feature announced by Apple yesterday.
From the product fact sheet: "Safari Reader removes annoying ads and other visual distractions from online articles."
On the other hand, maybe authors should take this as an opportunity to receive a clue. There must be significant demand for this feature or Apple wouldn't have put it in their browser. Perhaps you should reduce the clutter in your web pages on your own.