A new service by a company called LiquidID is mildly interesting.

One of the potential hazards of OpenID is that your email address might get compromised and then life won’t be fun anymore.

However, if you login with a LiquidID account, each OpenID site has its own alias through LiquidID. If your email gets compromised or gets really spammy, simpy remove that alias.

You can see more here (via ReadRightWeb).