The more i visit various web-sites, the more i want a single sign-on feature.
Every web-site thinks theirs in the most important. Every web-site insists that you create an account before you can do anything. StackOverflow, Serverfault, Wikipedia, WowWiki, Wowhead, MS Forums, CodeProject, CodePlex, on and on, ...
They all demand i create select a unique username, a password, and fork over my e-mail address. Then they insist that i go check my e-mail before they let me post, edit, download, click, comment, rate, etc. There is no reason to not let me use your site the instant i wander into it.
i just want them all to shut up. i want a single login that i can just use everywhere, with an e-mail address that is a black-hole so i never have to read their garbage.
OpenID seems to be that. But it was only possible once Google supported it. Before that, it was StackOverflow's own propritary login system - that they were too lazy to host themselves. Now that Google supports OpenID, it's actually conceivable that everyone will already have it.
These days, i loath having to create accounts on web-sites, and curse the operators who think i should have to create an account first.
Don't make me loathe your site, too.