If you have ever wondered whether an image or text is copyrighted or in the public domain, this chart from Cornell University is a great reference (and it was updated in January, 2010). Copyright is never easy to figure out, but at least this has all the rules and exceptions in one place.
ARTstor has announced that 833 images (69% of the roughly 1,200 projected total) from the Georgia O’Keeffe Museum are now available in the Digital Library [keyword search: okeeffemuseum]. Additionally, agreements have been reached with the following institutions and should be available by April (all image counts are approximate): Diego Rivera at the Detroit Institute of…
The Copyright Clearance Center has loads of information to help with copyright questions, including this 6-minute video that breaks down the basics. The Copyright Alliance is another organization with a very helpful website, including a section specifically for Educators.
Ever wonder if that manuscript, book, image, etc. is protected under U.S. copyright laws? The American Library Association has come up with a fantastic tool to help answer that question: http://librarycopyright.net/digitalslider/. It lets users scroll through numerous copyright terms for works published or created during different time periods and under various conditions.