[eridius]

I agree. But unfortunately, OpenID can magnify the problem for some people. For example, my girlfriend has at least 4 different Stack Overflow accounts because she can never remember which OpenID provider she used, so she keeps accidentally creating new ones.

[jes5199]

Yeah, that happens to me to. I need there to be a system that says "We've never seen that ID before! Do you want to link it to some other account?"

Which means maybe you should have a separate button for "I want to create an account here" and "I want to log in again here". I know that's heretical to the OpenID community, but I usually know whether or not I have some account on a site, but I usually don't know whether I typed in my openID url or hit the Google button.

[thomaslangston]

The simple solution is to setup a priority and stick to it.

e.g. Google > Twitter > Email >>> Facebook

[tszyn]

Exactly. I used to run a small StackExchange site. One day I had a look at my user dump and was surprised to see how many duplicate (and triplicate) accounts there were.

[Tichy]

Haven't been able to log in to StackOverflow for weeks.