What do you do to reduce the number or cost of meetings? (either as an individual or as an organization)

The main technique I have been using lately is preemptively blocking off chunks of time long enough to get something done (3-4 hours), and declining any meetings that are later scheduled over that time. This groups meetings together, incurring the "resume cost" once per group instead of once per meeting.

[0] http://www.paulgraham.com/makersschedule.html