I was at someone else's meeting last week that was a disaster...complete and utter disaster. The meeting was called, calendars (of busier people than me!) were cleared, an agenda was sent, but only a few people showed up.
We were all there in person, but only half the group was there -- prepared, ready to participate, and with an intention to collaborate. They showed up but didn't.
Made even worse by the fact that the meeting convener didn't show up either. I mean really.
It would have been better for him to cancel the meeting than actually hold it when he wasn't prepared. Instead of an empty 2 hours on the calendar, now he has at least 4 people who won't bother showing up (in any sense of the word) next time.
Show up. Come prepared -- read the material, know why the hell you're in the room, have a point of view, at least come with your calendar so that you can discuss schedules.
(p.s. you can buy this tshirt at zazzle)