Quincy's Thomas Crane Public Library offers the BEST museum pass program!  Great for family outings and entertaining guests from out of town!  Library card holders may reserve passes or pick up coupons allowing free or largely discounted admission ($7/person or less!)  to twelve of Boston's greatest attractions!  I know that other area public librarys have similar programs; Quincy's includes: the Aquarium, three area zoos, MFA, Museum of Science, the Children's Museum (new and improved!), Boston by Foot, Plimoth Plantation, and more!  Check it out!