[gvkv]

UI issue: Why do I need to come up with yet another username? I've never understood why websites don't just let username == email with an optional alias. I understand that OpenID or ClickPass might not be worth implementing but in my view, this username thing has got to stop. To this end, I refuse to sign up for any service that requires me to login via username (other than email). It's too bad too, because this looks very cool.

[imp]

I'm sorry to hear that you don't want to register. I agree that usernames are frequently unnecessary, and for other sites that I've created I avoid them.

However, I think it's useful for this website because you get a profile page with a URL that uses that username. For instance, here is mine:

http://curiousreef.com/kday

Sure, and email + alias could work also, but I really wanted people to have their own vanity URL, and this seemed to be the easiest way to do that.

[gvkv]

A unique alias is fine in circumstances such as the one you've given--my point is about account creation and logins. There is no reason you can't use an email as a login and then require the user to give a unique alias to use in their URL. FogBugz (On Demand), to cite one example, does things this way. You login with an email but when you sign up, you have to give a unique corporation name and the app generates a subdomain of fogbuz.com; e.g., mycorp.fogbugz.com.

Anyway, I really like the idea of what you're doing, but as time marches on I am becoming increasingly zealous over this issue. Retooling your app at this point is probably too much work given that most users don't have the same conviction as I do but since you asked for feedback, I'm giving you my 2¢.