I agree, but I think people should still maintain politeness even if the interviewer appears to be doing a less-than-awesome job. Even if you already know halfw

I agree, but I think people should still maintain politeness even if the interviewer appears to be doing a less-than-awesome job. Even if you already know halfway into the interview that you're not taking any job-offer from them... just go through it 'till the end. If nothing else, it's an experience and maybe you'll pick up more info on how to avoid those companies in the future.