Moments ago, Google launched a new feature called My Search History that automatically remembers every query and search result page you viewed, making everything searchable. In my opinion, it's the strongest personalization offering from a major search engine to date. See my SearchDay article, Google Personalizes the Web, for a detailed run-down of the new service.
Search Engine Watch members will also want to read Danny's article, Search Personalization: A Marketer's Perspective which offers tips for search marketers on preparing for the coming of personalized search results. Click here to learn more about becoming a member.