Yes, I understand that frustration. Really and truly, the only reason I used a proprietary format, instead of a more commonly used format, or a database, was that I was trying to teach myself a few things as I programmed. I wanted to learn how to use serialization (writing a .NET object to a file on disk).
As for CVS, I'll try to do some researching on it. I'm sure there are plenty of sites that describe the format. I just need to bone up on it. I also thought about a feature where your archived contacts could be uploaded, by the application, to your website via FTP, provided you supply the appropriate username, password, and directory. I have some code that I've successfully used to upload files.