But don't take my word for it

There are a few web sites that are attempting to become complete Art histories, but in a different model than the traditional survey textbook.

ArtHistoryUnstuffed is based on a blog and podcast model--it's got a single author with a vision and control.

smarthistory is slightly more wiki-like. It has a number of contributors, allows users to submit content, and includes multi-media presentations. It's attempting to become an online textbook and course unto itself, not just to supplement a traditional book or course. The cool thing about smarthistory is that it's got more than you could ever want. The problem may be that it's got more than you can possibly fit into your schedule. Or your brain. (Hint: the Flickr pool may be a great place to get good notecard images.)

Have fun with both, and let me know if you come across any other sites of this type.