title: LINQ - writing a query with distinct and orderby
body: <p>I'm quite new to LINQ.</p>
  
  <p>Suppose that I had the following table:</p>
  
  <pre><code>Incident 
  
  ID DeviceID Time          Info
  
  1    1      5/2/2009    d
  
  2    2      5/3/2009    c
  
  3    2      5/4/2009    b
  
  4    1      5/5/2009    a
  </code></pre>
  
  <p>In LINQ, how could I write a query that finds the most recent and distinct (on Device ID) set of incidents? The result I'd like is this:</p>
  
  <pre><code>ID DeviceID Time           Info
  
  3    2      5/4/2009    b
  
  4    1      5/5/2009    a
  </code></pre>
  
  <p>Do you have to create an IEqualityComparer to do this?</p>