It’s all for nothing if you don’t have freedom from your schedule sometimes. The 50-Minute Meeting is a great idea. My method for effective meetings is to have an agenda, start on time and finish on time no matter what. I also schedule “work” time in my calendar so that meetings cannot sneak up on me. The bane of my existence are the surprise meeting shoehorned in because I had a free 30 or 60 minute block. Truly awful.
Andrew Sullivan had a similar post about how writers hate meetings (see here). Breaking up the day really craters productivity. Maybe there should be allocated meeting times (like classes) that people enroll in. That way, you know they are available.