title: NBuilder - creating more Random types e.g. EmailAddress
body: <p>Right now I am using NBuilder to generate Customers in my mock repository. Unfortunately the only option I have for random strings seems to be .Phrase()</p>
  
  <pre><code>var customers = Builder&lt;Customer&gt;.CreateListOfSize(10)
                                 .All()
                                 .WithConstructor(() =&gt; new Customer(
                  r.Int().ToString(),
                  r.Phrase(5),
                  r.Phrase(15),
                  r.Phrase(15), // EmailAddress
                  r.Phrase(15),
                  r.Phrase(15),
                  r.DateTime()
                  ))
                  .Build();
  </code></pre>
  
  <p>I would love to be able to generate semi-sensible data, like an email address.
  Is there a way to customise NBuilder to do this, or should I be piecing together two .Phrase() calls with an @ symbol?</p>