Christopher's Guidelines For Meetings:
"Meetings should never be used to present information, only to make decisions about information presented prior to the meeting."
"Meetings should have a written objective and agenda, which should be distributed in advance. Preferably the distribution takes place far enough in advance that the participants have time to actually read up on the subject matter."
"The meeting should always start on time. If you are late, you should find yourself locked out."
Check out the blog of 37 signals. It is interesting.