Cool Public Domain Image: Carnival Ride

This photograph is from the Library of Congress. It is found it the John Margolies Roadside America Photograph Archive and has been released into the public domain. 

Disco Star Ride at Seaside Heights, New Jersey

As for using this image, details from the LOC:

Publication and other forms of distribution: John Margolies made the photographs in the John Margolies Roadside America Photograph Archive. The Library of Congress purchased the intellectual property rights for the photographs with the archive and, therefore, there are no known copyright restrictions on the photographs. Privacy and publicity rights may apply. Photographs of sculpture or other works of art may be restricted by the copyright of the sculptor or artist.

Access: Subject to P&P policy on serving originals. Digital images are used in preference to the original slides, which are kept in cold storage for preservation purposes.

Reproduction (photocopying, hand-held camera copying, photoduplication and other forms of copying allowed by "fair use"): Subject to P&P policy on copying, which prohibits photocopying of the original color photographs.

Credit Line: Library of Congress, Prints & Photographs Division, photograph by John Margolies, [reproduction number, e.g., LC-MA05-1]

For more information, please read: Copyright and Other Restrictions That Apply to Publication/Distribution of Images: Assessing the Risk of Using a P&P Image