Gmail search operators: OR, in:anywhere and others

Gmail's search operators are resemble those of Windows Desktop Search. I suppose we're heading towards some kind of convergence.

The interesting ones are:

• to: (obvious)
• has:attachment (more useful than one might think)
• in:anywhere (when it might be in spam filter or trash)
• after: and before: (dates are yyyy/mm/dd - my favorite date format!)
• OR: yes, Google has introduced the Boolean OR. At long last ...