I'm sick of spam, and I'm sick of hearing about it in the media. I've read many proposals and they usually rely on legislation (which will never work) and filters (which can never be 100% effective).
So here's my idea.
Forget trying to patch up the current email system. Start a new one. It only needs four things to work:
1. The system
2. How to get everyone to use it
3. How to make it profitable
4. How to stop spammers from accessing the system
5. Who can make it happen?