My rule for gmail... I type gmail.com then log in. That's the only path I take to log in. I never click a link and log in, etc. really I do this for most sites I use.
Shouldn't this still work? I think if you are signed in on gmail, then if a third-party site asks you to log in, it will pop up a window with just a button saying "authorize", you should not be asked to enter your password again...
