Ideas for preventing mid-year volunteer burnout

Moms say NO to volunteering!  In case you missed the buzz before the holidays, both the NYTimes and CNN ran articles about moms so overwhelmed by over-volunteering, they quit cold turkey.  The Times article hit a nerve and was the #5 most emailed article for 3 days!  Here's a post with links to both and ideas for preventing burnout among our volunteers (and I was interviewed too):

     Avoiding Volunteer Burnout

What does your school do to prevent volunteer burnout and re-energize volunteers mid year?