title: Phone number normalization: Any pre-existing libraries?
body: <p>I have a system which is using phone numbers as unique identifiers. For this reason, I want to format all phone numbers as they come in using a normalized format. Because I have no control over my source data, I need to parse out these numbers myself and format them before adding them to my DB.</p>
  
  <p>I'm about to write a parser that can read phone numbers in and output a normalized phone format, but before I do I was wondering if anyone knew of any pre-existing libraries I could use to format phone numbers.</p>
  
  <p>If there are no pre-existing libraries out there, what things should I be keeping in mind when creating this feature that may not be obvious?</p>
  
  <p>Although my system is only dealing with US numbers right now, I plan to try to include support for international numbers just in case since there is a chance it will be needed.</p>
  
  <p><strong>Edit</strong> I forgot to mention I'm using C#.NET 2.0.</p>