Teen Volunteering

I work at a local non-profit and we are getting calls all the time from middle school and high school students seeking volunteer opportunities. Some are looking to volunteer to get experience before applying for their first paid job, others are doing it for college applications/scholarships, others for court requirements, and the majority are looking for short term commitments to fulfill school service requirements. I have a few opportunities but am curious to hear more about other teen volunteering options in the Bay Area. Where can teens volunteer? What types of opportunities are out there for both long term and short term volunteering?