After point 4 have a (BIG) link to go somewhere, e.g. "see if I already have an OpenID"!!!
After explaining how it works, point 1, 2, 3, and 4, why leave the reader in the middle of no-where???
First thing one wonders after reading is whether or not he already signed up somehow. That's the first thing you say on your homepage "Chances are you already have an OpenID but don't even know it! No problem — we'll walk you through using your OpenID for the first time." NOT TRUE
You inform about how to use it, once you know you have an OpenID, but you don't give any hint how find out if you actually already have one!!!
I think this is the third or fourth time (in four years!!!) it makes me go away without even trying. I still don't know what I should fill in in stead of "bobsmith2000".
I tried with my google account but I get Sorry, that is not a valid OpenID. Please ensure you have spelled your ID correctly.
Chris Messina commented
Where are you trying to sign in?