Art and Art History 

Winged Victory by Carl Roseberg

Art Institute of Chicago Thousands of images from past and present exhibits as well as the permanent collection with audio and video Musecasts (podcasts).

Art Museums Worldwide Great listing of museums and their links around the world.

British Museum (London) Online tours of artwork from every continent with over 1 million images available.

Getty Museum (Los Angeles) Huge collection of 17-20th century works, as well as an extensive Greek and Roman Collection with a large video collection on the museum exhibits, conservation, and how art is created.

Hermitage (St. Petersburg)With over 3 million items from around the world, virtual tours of their collections and buildings, and thousands of images from pre-historic to the 20th century.

Louvre Website includes images, virtual tours, and numerous databases: Prints and drawings database, American art database, database of works in French Museums, and a database of past and current exhibits.

Metropolitan Museum of Art (New York) Inludes more than 2 million pieces of art with information and images on over 30,000 available in the Collection Database as well as audio podcasting with slideshows.

Museum of Fine Arts (Boston) Collection of over 22,000 pieces with interactive tours.

Museum of Modern Art(New York) Extensive online exhibits and projects in sculpture, photography, media and film, drawings, paintings, and architecture, with great podcasts of their exhibits.

National Gallery of Art(Washington DC) Includes thousands of online images, streaming slideshows, audio and video podcasts and online virtual tours. Can search extensive images by artist, title, or provenance.

Victoria and Albert Museum (London)3000 years' worth of amazing artifacts from many of the world's richest cultures including ceramics, furniture, fashion, glass, jewellery, metalwork, photographs, sculpture, textiles and paintings. (Thousands of images from their collections)