Banner all over the site when you've signed up but not confirmed
One of the user testing people signed up, got the notification text that they had been sent a confirmation email, and then went off clicking around the site trying to figure stuff out.
One thing we could do is put a state flag on the session that says that the user has signed up but not confirmed. When that flag is set, we could show a warning banner like "You have not confirmed your email address yet! Check your email or resend_confirmation."
"Check your email" could link to Gmail, Yahoo or Hotmail if we know who their email provider is.