Alta Vista Refine
Enter your search term or terms, from either the Simple or Advanced Search screens, and click Refine. You'll see Refine's List View, which lists topics in order of their likely relevance to your initial search.
Specify whether to Require or Exclude a topic from the drop-down menus provided with each topic. You don't have to do this for each topic--just the ones you specifically want to require or exclude.