I've been in enough meetings to know that not everybody knows how to run them. (or at least how I think they should be run ;) Meetings are important, especially face to face, in order to define actions or gather requirements, build consensus in order to make decisions, keep people updated on where things are at, make sure the project is running smoothly and on time, catch problems before they're catastrophes, etc. Unlike some people, I don't think meetings are evil, but I do think that they can be misused and be unproductive when not run correctly.
Here's some things I try to keep in mind: