Harvard Law School has a page with links to archive webcasts, including speakers like Ken Starr, Al Sharpton, and Sandra Day O'Connor, and events like the Berkman Center's 2002 Internet and Society Conference.

The Wisconsin Supreme Court has a webcast of the audio portion of oral arguments, which I've added to the list of courts that webcast. You can also read advance summaries of cases set for argument, or review the audio archive, which dates back to September 1997. Too bad we can't listen to the 1879 argument in the case of Miss Lavinia Goodell, the first female lawyer admitted in Wisconsin, after a lengthy court battle resulted in a 4-1 decision in favor of her admission. The dissenter, Chief Justice Ryan, apparently took a dim view of women in the legal profession. According to Miss Goodell, the Chief "bristled all up when he saw me, like a hen when she sees a hawk, and did not recover his wonted serenity during my stay. It was fun to see him! I presume I was the coolest person present."