The present invention is directed to enhancing a user's interaction with a physical document, such as a page of a book, by supplying the user with additional information related to the physical document in a simple, easy to use fashion. Exemplary embodiments provide this additional information as digital...http://www.google.com.au/patents/US6781069?utm_source=gb-gplus-sharePatent US6781069 - Method and apparatus for virtual interaction with physical documents
