I love this pattern - I think it was Slashdot I first saw it on - but it still suffers from the same problem. What do you label the button - "sign up / login"?

I love this pattern - I think it was Slashdot I first saw it on - but it still suffers from the same problem. What do you label the button - "sign up / login"? It's still easy to miss that it's also for login when scanning.