Michael Sandel's Justice website is a superb example of how academics can use the Internet to reach out to a world audience. Based on his renowned Harvard lecture course, it combines slick recordings of his 12 lectures (first 3 available already via a YouTube link) - which are also being broadcast on public service TV in the States - with associated reading lists, back up material discussion groups, etc. And his new book: Justice: What's the Right Thing to Do? Eventually all academics should be able to create resources like this...and the exclusive and insular idea of a University (symbolised by those Oxbridge colleges with high walls and gatekeepers) can evolve. Although he believes the website isn't a full substitute for sitting in that lecture theatre in Harvard, it is as close as most people will get to being there, and certainly one of the most important attempts to bring philosophical debate to a wider audience in recent years. Some of Hubert Dreyfus' worries about virtual learning may still apply, but the experience probably beats what most university students get these days in the lower-ranking colleges.
In the UK, many of us still look back fondly to Bryan Magee's BBC television series 'Men of Ideas' (not a title that would work today) and 'The Great Philosophers' (search 'Bryan Magee' in YouTube for long extracts), but since then, apart from Michael Ignatieff's interviews with thinkers, philosophy on television hasn't really achieved what it might have done (instead we've got the sugared pill of biographical sketches which tend to play down the ideas, or else philosophy lite, or philosophy as self-help). TED.com's popularity, though, should make those commissioners realize the appeal of dynamic speakers presenting ideas they believe in.
It helps, of course, that Sandel is an excellent communicator, engaging in a quasi-Socratic dialogue with questioners even in a large lecture group. In fact, his presentation is so good, that it is easy to be drawn into his worldview (as an antidote, read Michael Sandel Wants To Talk To You About Justice which includes some interesting pointers about where he is coming from and why some philosophers disagree quite strongly with his approach).
Sandel gave the 2009 Reith Lecture Series on the theme of 'A New Citizenship' (basically, the themes from his Justice course). You can listen to all 4 Reith lectures here.