RUMOR CONFIRMED!!! For a limited time you can walk into any of these for free:

Conservatory of Flowers, SF
California Academy of Sciences, SF
Walt Disney Family Museum, SF
Museum of Contemporary Art, LA
Museum of Contemporary Art, Chicago
Adler Planetarium, Chicago
The Field Museum, Chicago
Museum of the city of New York, NY
Museum of Arts and Design, NY
National Building Museum, DC
Portland Children's Museum
Portland Art Museum
Pittock Mansion, Portland

If you are around one of the following 13 museums, you will get a Field Trip card with "Free Entry" in the title (check the 'nearby' tab). Show the card on your phone to the admissions staff and they'll take care of the rest.