Are we teaching too much?

In many European and Asian countries, teachers spend no more than half their work week in classroom instruction. They spend 17-20 hours per week teaching and devote the remainder of their 40-45 hour work-weeks to planning, collaboration, meeting with students, and observing their peers (Darling-Hammond, 1999). In the United States teachers average 5 to 10 more hours per week in the classroom than their counterparts in top-performing European and Asian countries, and thus have less time for planning together, collaborating, and implementing job-embedded professional-development strategies that are common in other countries.

Are public school teachers given too great a teaching load?
What would you do with 5 to 10 hours of non-teaching time per week?