> People seem to think its fine to walk out of an interview early ... but how do they feel if the interviewer ends the interview early, or your "full day" of interviews is cut to just 1 or 2 hours because they just didn't think it was a good fit?

Uh this happens a lot. In fact, when I was looking for my first entry level job in a new city this was semi-common. Many interviewers or hiring managers will get hostile at you for the smallest things, like failing to get the catch in a puzzle question or because they dislike something about your resume. As soon as that one person would leave the room, it was usually followed by someone from HR coming back and politely telling me the interview was over. As a worker you owe a potential employer nothing and have the right to leave at any time you wish, regardless of how intimidating some people will be when you say you want out.

I've had this very thing happen to me. I was surprised when it happened as it was a first for me. That said, I think it's becoming more commonplace, particular in small to medium size companies who are very sensitive to wasting their own developers' time.

If it's becoming accepted practice for companies to dismiss interviewees early, then I see no reason that interviewees should not be able to do the same (politely and professionally, of course)

I wouldn't be pissed at all. I can take the rest of the day to gather my thoughts and not feel like they wasted any of my time with other interviews that weren't going to lead anywhere. I'd actually appreciate the fact that they were upfront instead of stringing me along.

I think that since a company is deciding on the structure of the interview day they have a responsibility to be transparent about the process beforehand. This is a different situation to the person being interviewed.

For my current company the invitation to the interview says that if they like you then you will be invited to continue to another stage of the interview after lunch (they deliberate/discuss while you have lunch).