The first is through the Museum of Modern Art and its called Modern Teachers. It doesn't contain extensive art information but it does have a really cute interactive cartoon called Destination Modern Art which is similar to the animated flash video on the National Gallery of Washington's site. As you pilot your alien friend through the gallery you can stop and 'look, listen, and interact' with the various artworks hung on the gallery walls.
The second site is called Artbabble and what I found to be of particular interest is the fairly extensive list of artists (under the artists link at the top of the homepage). When you click on a specific artist, which FYI is alphabetized by their first names and not their last, you get a few short contemporary high res. videos about the artist and their work. None of the videos I saw were that long, but it just might do the trick as a hook or icebreaker when introducing an artists or a specific work with your students. Below is one of those clips, about artist Jeff Koons from the site:
The third site is a new blog I came across from the art teachers listserv it is for Art Education Videos suitable for grades k-12. I was perusing it and came across a 2-minute video I particularly liked on Herb Williams, an artist who does all his sculptures out of crayola crayons! On the side search bar you have to click crayon sculptures.
Lastly here is another site from the listerv, called Glogster which I am about to check out right now. Supposedly its a great resource for creating/altering SMARTBOARD activities. But I'll let you know in a few days...In the meantime, Enjoy!