Well, if you're interested in being a fly on the wall, check out <a href="http://www.twitch.tv/roll20app" rel="nofollow">http://www.twitch.tv/roll20app</a>
You can watch the recorded livestreams from Riley & Co.
They also broadcast live bi-weekly, and there's usually a post here in the forum letting you know when the next game's coming.
If you're interested in GM'ing (or even playing for that matter) you can also seek out games run by Chris Perkins (He's my DnD hero) on YouTube (I'd recommend the Robot Chicken games - with, or without commentary), or find the Penny Arcade podcasts.