Automating joining&leaving mailing lists

The lack of comfort when joining mailing lists is annoying. If anybody wants to make me a little bit less grumpy, try the following:

• design a XML Scheme / file format to describe a mailing list (and especially how to join and leave it)
• register a corresponding mime type in KDE
• add a handler for that file type in KMail, or write a stand-alone app that uses the KMail backend
• when somebody clicks on a link with that mime type in Konqui, start the handler
• the handler will, after some GUI to explain it to the user and asking for permission, create a folder for the mailing list in KMail, create a filter for the mailing list, write a mail to the registration address to join and reply automatically to the confirmation mail
• KMail should have a 'unsubscribe' context menu entry that lets a user unsubscribe automatically

That would be useful... The next step, of course, would be a more comfortable way of browsing and finding mailing lists. KMail could have a build-in list of mailing lists (or download one) so people don't need to search for them.