Where to find latest videos of colloquia or other talks in your field?

I am wondering how I can find and keep updated of the latest colloquia and talks videos. I imagine that schools may take videos of talks they hosted and upload them somewhere. Of course not every school/department does this, and this depends on the field that one is interested in. But if I know where they are, I can check for updates manually, or set up some sort of feed/automated notification with keyword filtering.

To be more clear I am not looking for videos of online classes (e.g., http://coursera.org), but talks about the latest work in one's field.

The only ones that I found are Stanford and UC Irvine, but I suspect there must be more out there that are not on youtube.