I agree... I usually don't even entertain the idea of an interview unless I already know the salary range. I don't want to waste their time or my time.

There are exceptions, of course. I may interview for a job that is particullary interesting to me or it's super close to home without knowing the salary ahead of time. I also say that after what you think is a killer interview would be the time to negotiate salary while your performance during the interview is fresh on their minds. You might be able to get more than advertised if you made a really, really good impression.