I wanted to share a website I discovered recently and now love. It is an art appreciation/art history website called Smarthistory.
The backbone of Smarthistory is (at this point) over 400 videos on different pieces of art, artists, or art period or concepts. The home page basically organized these by timeline, so they fit in well as an art history resource, or as a way to quickly add art content to a history lesson. However, inside the website you can search for videos not only by time, but by style, artist, or theme--which makes it a very flexible resources for incorporating art content in other kinds of lessons as well.
One way this website really stands out, however, is that there is an entire section on how users can make their own similar videos. It covers the technological tools to work with images and video, advice on approaching presenting art, tips on interviewing art experts, and even philosophical discussions on the difficulties of combining text and educational resources with the experience of appreciating a piece of art. This helps both students and teachers be not only a consumer of Smarthistory's videos, but a potential creator of their own reflections and mediations on art.
Smarthistory also has some suggested curricula: a 15 week Art History Survey (Western Culture) and a 15 week Art Appreciation Survey (again, Western Culture). These were developed for the college level, but I think they could be very helpful, perhaps not for middle schoolers, but definitely for high school, especially those preparing for AP exams in related history or art areas. For teachers, Smarthistory has been developed under a Creative Commons license, and they encourage teachers to embed their videos in their courses and online syllabi (with proper attribution, of course--but they give you the proper citation on their website.)
Smarthistory was developed by some experienced teachers of art history/art appreciation, and it shows. However, they have recently merged with Khan Academy, which I think is a win/win for both groups. Khan Academy gives Smarthistory more technological and institutional support, plus access to a much larger user base, while Smarthistory expands Khan's more math/science/technology focus into a strong curriculum in the humanities, and gives a softer, artistic edge to their rather geeky presence on the web.
All in all, I think it is a very well done project that adds a lot to our online resources on Western art.