Short answer: don't have meetings. Long answer: work in the same room together for a few hours a week (10-20). This way as questions come up they will get resolved in context. Announcements, presentations and other broadcast-type things can be made at coffee break. Start having meetings after this model stops scaling.
I disagree with your short answer. Our 3 person company has a weekly meeting every Friday from 1 minute to anywhere to 30 minutes depending on if anything needs to be discussed in more detail. It's a very good idea to get together once a week outside of just working together to go over the week's happenings even if it's only for a few minutes. It serves to seal the deal of the week and get everyone completely caught…
It's a lot easier to stay focused when the other guy is focused.