This is why OpenID is such a good idea.
URL based Identifiers
It talks about how we should use URLs instead of E-mail as identifiers for ourselves. When someone gets ahold of your e-mail, they can spam the hell out of you. E-mail inherintly has no way built into it to identify who the send is, so you have to accept ALL e-mail, and then use other mechanisms to sort out the stuff you want. With URLs, if you get my URL you get nothing. You know who I am, but that doesn’t inherintly give you any way to contact me. If you are my friend and you can prove to me that you own a URL that I know you own, I can then allow you to contact me. This inverts the basic premise of E-mail, allows for authenticatin, eliminates spam, and is just a good idea. I’ll put my URL on my business card, and then I’ll decide what information you get about me based on other critera.
This is a very powerful idea, and has the potential to change the paradigm of web interaction. That’s why I’m learning about openID and such!