How can you be more productive in the meetings?

Pench,

Actually to host a good meeting is an art... and a lot of it have to do with knowing ahead of time about what's going to be discussed and keep the meeting as Michael Coleman told you on his response....Keep it on target.

Prepare meeting agenda, including minutes/topic, minutes total, decisions needed, options, pros/cons, in advance. Review with your manager(s), coworkers, requesting their opinions. Revise if needed. You can even decide which decisions you'd like in advance, go to each meeting attendee individually in advance. Talk with them, explain each decision needed, present your case for your desired decision. If you gain each attendees agreement individually in advance, then the meeting will be very fast. People hesitate to go against prior agreement.

As suggested by many above have an AGENDA with set times (to control the "wafflers"). Basically be very clear what you're trying to achieve!! As Joanna suggested where decisions are required canvass everyone first and perhaps limit the number of decisions per meeting. And don't be scared to finish early!!
This goes for both one off meetings and recurring meetings.

As facilitator:

1) Make sure that the agenda is distributed in advance
2) Make sure you have an actionable agenda
3) Know how to handle different personality types, this will help you to keep it on track
4) Don't dismiss 'irrelevant' discussions. Park it for a off line or side discussion. Outright dismissal will create discontent.

As attendee:

1) Go prepared. Read the agenda, know the agenda.
2) Inform the facilitator in advance if you have missed targets on action items allocated to you.

In addition to the valuable suggestions above, invite only those people who are absolutely needed in the meeting.
-They should be aware of the agenda prior to the meeting so that they can contribute effectively.
- If someone can provide status or information in email/personally without being present in the meeting understand their perspective.
- Meetings should be held for planned schedule and not extended to indefinite hours.
- Off topic discussions not in agenda should not be entertained in the scheduled meeting.