Europeana.eu allows you to search through dozens of cultural collections of Europe, including national archives, libraries, museums and other research centers. Simple or advanced searches return digitized texts, images, videos and/or sounds. Each item contains information as well as a link to the “original context” — its page within the originating organization. One great feature of Europeana is the ability to register and save items, searches, and tags.
Europeana is searchable but a prototype at this stage (with additional projects in progress, such as the experimental Semantic Search Lab with datacloud) and will evolve in response to users’ feedback.