Log in or sign up?
blog.leahculver.com
blog.leahculver.com
We (Weebly) thought of this problem early on, and we tried to simplify things by just requiring an email/password when signing up. What we found was that our users were extremely confused, because the sign-up form didn't look like a sign-up form. When doing usability testing, we found that users would stare at the page for minutes. "us: Just sign up..." "user: I can't see where to sign up", even when it was right in front of them. They saw two fields and assumed it was a log-in form, even when it said in really big letters "Create a new account".
Users don't read your page, they scan it. People expect the log-in form to be in the upper right and the sign-up form to be towards the center of the page. You should absolutely make your site scan-friendly.
Users do, though, get confused and try to use the sign-up form to login. Our solution? If the user enters credentials into the sign-up form that already exist (like the correct username/password combo), we'll just log them in instead of creating a new user. You can try it out on weebly.com.
I don't know if you've encountered that problem (rare, I know).
Since user intent is clear if they try to register a user name and password that are already in your database, rather than giving them a "that account already exists" error I just log them in straight away.
I'd probably ditch the radio buttons and make the header more eyecatching, with "Join Now?" clearly a link. Clicking it changes the form in the way Leah shows, probably with a quick Javascript fade so the user notices.
And yes, I'm aware HN has this problem, unless you go in and put your email in your profile.
The way you would go about logging in from that page is less clear than most websites.
When I was designing Memengo's homepage (http://www.memengo.com), I was trying to provide streamlined execution path for 3 different scenarios: see demo, register, log in.
I hate web sites that have tiny log in link in the top-right corner. After all, I usually visit home page to log in immediately, so I expect email and password fields to be provided right there.
To streamline sign up there is a need to ask as few things as possible, preferably on home page as well.
Potential users should be aware that there is a no-strings-attached functional demo one click away, so this area requires some screen estate as well.
The final design: 3 equally sized boxes on the bottom of the page: 1 click demo, Sign up (with all required fields), Log in (with all required fields).
Maybe it was just a function of our design, but the feedback was that people didn't read and thought it was a login-only form. People are just conditioned to seeing long sign-up forms. A username/password pair just screams "login"!
There is enough innovation in the rest of our app to worry about, we didn't also need to be re-inventing authentication. Our login and sign-up forms are now on two separate pages and we added "Remember me" and "Confirm password" to the respective pages. Both pages have a link to the other.
We're trying to funnel users through the workflow such that we can present the correct page the vast majority of the time. For example, many features can be tried before making an account, but you get to them by clicking "try it now". Once you have an account, you get to them from your dashboard. This way, we can reasonably assume a user is new if they aren't authenticated already when they go to use such a feature.
I hate the page LinkedIn shows when you're not logged in, it asks you to signup, and the login page is actually a different one. I find the call to action to register stands out, but they seem to hide the link to the login page. I never feel stupid when I encounter this, I feel like the site doesn't want repeat users, they want new user signups, and don't care if you end up recreating your account (this may explain why I've seen so many duplicate and inactive accounts on LinkedIn).
Login/Register button at top right
Depending on the nature of the application you may or may not need to worry about this (e.g., obviously irrelevant if the site has a user list that shows the login names).