An online course in Web Usability is available from the San Jose State University's School of Library and Information Science. You can get the course on iTunes U through the iTunes Music Store, but it's also on YouTube (search for LIBR-251) and the School's website.

I'm sure there are many similar courses, but this is just one I found recently.

• Carnegie Mellon's Open Learning Initiative offers free distance/online courses, some of which (Visual Communication Design, statistics, etc) are applicable to the ux field. You can find more details on this, and other, resources, in answers to the related uxexchange question Online human factors/usability/user experience training 2010

• The Learning IA section of the IAI's site is also rich in resources on this topic.

• Feb 16/10 update: Recently also came across the AMA's Interactive Webcasts which have some topics you may find potentially relevant, including some related to Customer Based Measurement, Incentives Online Customer Feedback Best Practices, Search Marketing, Engaging Users

The Open University in the UK has at least one course in Interaction Design. While I've not studied with them, a friend of mine studied the above module last year and really found it useful.

I'm in the information design program through onlinelearning.com. I've taken two courses thus far and am very pleasantly surprised at the depth of knowledge of the instructor (Hans Bergman) and the knowledge I've gained. The price is reasonable, too, for working stiffs such as this old woman.