Merlin, over at 43Folders, offers some no-nonsense advice for being able to add words like "effective," "necessary," and "worthwhile," when describing your meetings. This is good stuff. He opens his post by saying...
"...thought I’d share a few of my own tips for getting the most out of your meetings — primarily from the perspective of being the organizer and facilitator. For the love of God, please respect your poor colleagues’ time.
1. Circulate an agenda.
An agenda should show the planned steps that get the meeting from “here” to “there.” It helps the participants prepare appropriately and anticipate the kind of information they might need to produce. Most importantly, it works as a contract with the participants: “here’s why this is a great use of your time for n minutes.”
2. Have a theme.
Meetings shouldn’t be meandering tours of each participant’s frontal lobe (unless — well — unless that’s the actual agenda).
The only thing that I would add to Merlin's list is this: Don't schedule a meeting if you can accomplish the same thing around the office water cooler. Time is in such high demand. Meetings can actually kill your momentum if not placed appropriately and you aren't able to get in and out.