While flowing out some registration / log in steps someone on my team pointed out that we're asking the same information from users in both of those steps - an e-mail address and a password, what's the point in the steps being different?
This made me realize that in previous apps I've built, I've used different Facebook button to register and log in users, but on the back end the same function is used for both - check if the user exists, and if not, register them, else verify them.
Why can't that be the way that things work for normal log in forms? Doesn't it make more sense (nevermind that there's a preconceived notion of registering and logging in - just because it exists doesn't mean it's right) to just have one form to handle both cases? Have we reached a point where the user should just be able to log in to your site? Is it time to start pushing this type of interaction?