title: Having 2 Lists, how do you find overlap between them in C#?
body: <p>I'm using Visual C# 2010 Express.  I have 2 Lists of zip codes each of which do NOT contain duplicates in and of themselves (the list items are all distinct).  However,  when comparing the 2 Lists there is some overlap, and I want to make a third list that contains only the overlap.  Is there a method I can use to do this?</p>