Groupon deal of the day for Chicago is discounted memberships to the Museum of Science and Industry. For $55 you can purchase a one-year family membership (regularly $115). The family membership includes free admission for two parents and all children plus a guest. You also get free unlimited admission to the omnimax and discounted parking. There is also a single person membership available for only $40 (regularly $80). You can go HERE to check out this groupon. Enter your info then click on more cities at the top and click on Chicago.
I am really considering buying this Groupon, we have been wanting to visit the Museum of Science and Industry for ages and I think my little boy is finally old enough to really enjoy it. The museum does have some free days, but I vowed to never go to one of these museums on a free day again after we went to Shedd aquarium in Chicago earlier this year. Buying this family membership would save us about $16 just on one trip (including admission, 3 omnimax tickets, and discounted parking).