To be honest, I am surprised that nobody has suggested using serialization. You can use simple XML serialization to convert your class into an XML file or convert your List(Of Contacts) into a single XML file with multiple nodes.
Wow dday. This stuff is awesome! It would be great if I could learn this. Back when XML was coming in, I didn't like the format and tried to ignore the movement. Not the greatest idea looking back.

If I could wrap my head around this it would be an enormous breakthrough for me. For me, it would be a study that would take quite a while to understand. And I would probably work on it full time too.

Wow, what is ".Net Fiddle"? A place to store your code?

Also, I'm going to send you a PM in just a second.