Ask HN: Good examples of registration ui

[antigua]

I did some searching and found this link: http://ui-patterns.com/explore/collections/account-registration

It has some good examples but I wanted to hear your opinions on what works and what doesn't. I personally like HN and Instapaper's simple registration forms and was wondering why there aren't more services using similar sign up forms. Wouldn't having one field for an email address and collecting all of the other cruft after validation be easier for end users?

[huwshimi]

Here are my thoughts on registration forms:

You should always have absolute minimum number of fields required to start using the service.

Don't have any optional fields (there are plenty of better places to ask for that information).

If there is information required to use certain parts of the service then ask for it when they want to use that part.

http://tumblr.com and http://posterous.com examples of this. I'm actually a fan of the single password input too... I implemented a similar form recently: http://hellohype.com/accounts/register, only with a username field instead of a url field.

I'm not a big fan of going to the extreme of Instapaper though. They don't require a password at all, so a malicious user can access and modify another user's account.