Re: Another way to do it. . .
Ahhh, I get it, you're looking for a relative identity check, to possibly link posters under different aliases without necessarily getting a real identity. Hmmm...the more we kick it around, the more a formal registration system makes sense to pull all these pieces together. Your concern is solved by invariant names/handles (or perhaps a small range, the way AOL does its screen names), you get remembered customization, email address privacy, simplified form-filling....
Those are the benefits, but seems like people are skeptical of registration, or don't want to take the time, fear spamming, etc. How would you feel about registering for HabitableZone?
--Robert