The Yahoo! UI Library team has an increasingly robust video section of the web site called the YUI Theater. It includes presentations from JSON inventor Douglas Crockford, YUI engineer Matt Sweeney, Oddpost cofounder Iain Lamb and several others on topics such as "The New Hacker's Toolkit", "An Inconvenient API: The Theory of the DOM" and "Applying Ajax: Speeding the Journey from Idea to Information".
On the heels of launching v1.0 of Firebug, a handy Firefox extension for working with front end code, author Joe Hewitt visited Yahoo! to give a power-user demo. The YUI team captured the talk on video, uploaded it to the YUI Theater, and now we can all get the tour. Here it is below:
There's also a growing YUI Library MyBlogLog community forming. You can join that here.