title: Best UI for Search/Filter/Boolean expression
body: <p>There are some simple ones, some complex ones, but I cannot find the gold standard. 
  Can anyone point me to "the best" way to let a user define a search criteria (or filter) to retrieve results?</p>
  
  <p>This is complicated since:</p>
  
  <ul>
  <li>Need to support about 10 different types of elements</li>
  <li>Support And, Or, Not</li>
  <li>Parenthesis (a killer to 95% of the population)</li>
  </ul>
  
  <p>As an example I looked at MorningStar premium fund filter, it is ok but not web2.0 (ajax, JQuery.. in other words, not cool) and it handles parenthesis poorly.</p>