Wanting to use OpenID, but concerned about some of the problems? Take a look at LiquidID, which combines the single sign-on and universal identifier features of OpenID with management tools to help you manage your ID with more precise tools. When you sign up for an OpenID at LiquidID, you can use it just like any other OpenID. The key difference is that LiquidID proxies your real email with a unique throwaway email address.
After you log into an OpenID-using site, any mail the site sends you is proxied through LiquidID. If the site annoys or harasses or spams you, you can simply delete them off your LiquidID account and that’s the end of it. As an added bonus, you can also create general purpose aliases to hand out in place of your real email address anywhere you like.