title: Recursive List Flattening
body: <p>I could probably write this myself, but the specific way I'm trying to accomplish it is throwing me off.  I'm trying to write a generic extension method similar to the others introduced in .NET 3.5 that will take a nested IEnumerable of IEnumerables (and so on) and flatten it into one IEnumerable.  Anyone have any ideas?</p>
  
  <p>Specifically, I'm having trouble with the syntax of the extension method itself so that I can work on a flattening algorithm.</p>