If you have a penchant for playing in the dirt and would like to contribute to area parks there are some upcoming volunteer days for the King County park system. All but the first date (which has already passed) are in October. The county is looking for people to help with planting native species in restoration projects. If that work sounds a bit too physically demanding, the first date is for weeding potted plants in a park nursery.
Go here to the King County parks blog for details.