I didn't sleep in a Holiday Inn, but I am a lawyer.

All original works have a copyright. The inclusion of the copyright symbol (c) or words to that effect convey additional rights under the law, but is not required to gain the law's basic protections.

Fair use covers many uses as described in other posts. Posting your own pictures of casino chips can easily be fair use. Posting someone else's picture of a chip would be fair use for the chip design, but it may get you into trouble because a photo can be a creative work. Just because anyone can enjoy a view of the Grand Canyon doesn't mean photographs of the Grand Canyon are fair game for reproduction. Scans - where there is little or no artistic contribution to the composition of the shot - are being litigated to determine whether they have protection.

If a picture is in the public domain, others can use it and you can use their pictures (since they don't own it) - but if they have added enough to make it a new original work, they have a copyright in their contribution and your use may wrongfully infringe. For example, a picture of the Mona Lisa is public domain. Mona Lisa with a beard can have some level of copyright protection.

Google doesn't necessarily use photos - it posts links to locations where those photos are used under the theory that it is fair use to point computer users to those locations. Other websites, such as Facebook and Google+, include within their user agreements a provision that allows those places to use or even sell photos you post. Family photos posted on by Americans on FB have ended up in supermarket ads in Europe.

All of the copyright laws have potential for conflicting interpretations in different districts and circuits until the U.S. Supreme Court issues a definitive ruling binding on all courts. If the federal court in New York rules one way, a court in Illinois might still rule differently.

Fair use is constantly being tested in the courts. It can be very expensive litigation, and the free advice I have just given you will not prevent you from getting sued. What I have said applies to the U.S., but not necessarily to all countries (although treaties have attempted to standardized some concepts). In addition, even if a picture does not carry copyright protection, a service like the Chip Guide should - and I understand does - consider the moral fairness of using pictures that might be "fair use" under the copyright laws but that were still used without the original owner's permission.