title: how to cache an xml file using c# 4.0
body: <p>I need to cache an xml that I am reading.  I'm using C# 4.0.  Can someone please suggest the most elegant/ best way to cache the xml file.  The cached file needs to be a singleton but the wrapper should probably be a transisent lifestyle.</p>
  
  <p>many thanks,
  James</p>