Saturday 9/25, as part of a nationwide celebration organized by Smithsonian magazine, general admission to some Chicagoland museums is free to guests who present a Museum Day pass (available for free online). Local participants include the Museum of Contemporary Art, Adler Planetarium, Intuit: The Center for Intuitive and Outsider Art, Loyola University Museum of Art, and others; go here to print a ticket, which is good for two people. A full lists of participating local museums is available here.