How Do You Get Your Clients to Focus?

What do you do when you're part of a project with clients who can't (or seemingly aren't able to) FOCUS?

As in not making everyone at a meeting go over a documented design decision for the fifth (or eighth, or tenth) time? 

Or not being able to clearly define the parameters of a project even after there have been dozens (literally!) of meetings to try to get enough clarity on the subject to productively move forward.

I know that the horrid economy is stretching resources and forcing museum folks to become even crazier multi-taskers, but at what cost to exhibition content development, and definition of project tasks?

In any event, I thought I'd throw open the question of "How do you get your Clients to focus?" to the witty and urbane ExhibiTricks readership.

So please post your ideas, or any resources or techniques for finding focus with clients in the "Comments" Section below.

Thanks!