Persistent Online Identity
OpenID, OpenSocial, Disqus all seem to point to the inevitability of persistent online identities. I imagine this POLID as something that will follow you from site to site, and be easily aggregable into a lifestream or personal history of web interactions.
This probably raises privacy concerns, but (Chabo and I have agreed) privacy is obsolete. Privacy is only going to become increasingly difficult to maintain, and it runs counter to transparency. I think transparency is good and the real way to deal with issues that privacy concerns seek to address is to combine more transparency with tolerance of deviant but harmless behavior.
Anyway, aside from that, I think the concept of POLID is good because it adds an element to the web that has been heretofore lacking: accountability. It adds the weight of history to online interactions, and I think the implications for this are only good. It could mean the end of spam, trolls, and a general increase in civility in online interactions, without even necessarily sacrificing anonymity.
I don't know exactly what the mechanics of this would look like, but here are a couple of ideas:
In comment systems, all comments under a certain 'identificationicity' (some function of the history-weight of a POLID attached to the commenter) would be subject to admin review before being published.
You probably wouldn't even take emails from addresses that aren't attached to a POLID.
You could establish multiple POLIDs if you wanted to, thus keeping the possiblity of an anonymous online presence. But even these alternate anonymous POLIDs would be subject to being flagged as spammers or trolls.
I guess the tricky part is the initial bootstrapping of a new POLID, but I think OpenID fixes this by associating your ID with a website or something (I've looked into OpenID several times but still haven't figured out how it works exactly).