Seattle Public Library has started a new program that allows you to reserve an admission pass to participating Seattle museums online at no charge using your library account. You can reserve up to 30 days in advance.
Participating museums include the Burke Museum, the Center for Wooden Boats, the Children's Museum, EMP, Henry Art Gallery, the Log House Museum, Nordic Heritage Museum, Northwest African American Museum, and Wing Luke Museum. Sadly, no Seattle Art Museum (yet) or Science Center (King Tut!).
You can get one pass per week per library card, and only one pass every 30 days for the same museum.