Larry Osterman has a great post today about Types of testers and types of testing.
This is a great overview of what testing *should* be in most organizations. :-) I have worked at exactly two places that had any kind of dedicated testing team. The first place had a team of 2 testers. They were pretty good, but inexperienced. The second place had a team of 1 and she was about as clueless as they get. Maybe someday I'll get to experience a dedicated, experienced testing team, but I'm not holding my breath.
Anyway, his post is a great read.