John Satter posts an extensive list of nearly 60 advanced search query modifiers, most of which are shared by all three engines. The options run the gamut from MSN's
"hasfeed," which pulls up documents that are storing RSS or Atom feeds on a site; to "inurl," which returns documents that contain the specific search term in the URL; to the more obscure
"rphonebook," which creates a list of residential phone listings for the keyword (and usually a state).
Playing around with this myriad of advanced options can provide insight into new keywords to rank for; possible unwanted search streams a given site may be ranking for; and a look at the nuts and bolts behind a competitor's ranking strategy.