I am guessing because he used different ClickPass providers the first time he logged in using different computers. I have been tripped up by this before on othe

I am guessing because he used different ClickPass providers the first time he logged in using different computers. I have been tripped up by this before on other sites and have found it fustrating. I had something similar happen when I reviewed a local restaurant (Mirth Cafe!) on Yelp. At first, I thought I could just write the review and be done since Yelp recognized that I was logged into Facebook and displayed the fact. In fact, that doesn't equate to a Yelp user account, which I apparently already had. Linking the Facebook account looked like a pain, so I just dug through my email to find my old account. Moral of the story? User management is tricky at best and a nightmare at worst -- really take the time to think it through. My impression is that users work in much the way a stream of water does, by following the path of least resistance. And remember, water doesn't usually flow back after flowing by. Sorry for the long rant; I don't mean this as a criticism of HN, just a frustration of mine.