As Sean mentioned yesterday, earlier this week the two of us recorded an episode of bloggingheads.tv, which appeared this morning and can be viewed below. Although Sean is a veteran, it was my first time, and I wasn't really sure what to expect, and as a result I was a little apprehensive about recording it. However, once we got going it was very enjoyable, and rather quickly it no longer felt so odd to be chatting over the phone while staring at myself on the monitor. An hour sped by as we discussed the constituents of the universe, the mysteries surrounding baryonic matter, dark matter and cosmic acceleration, and just touched on the anthropic approach to the cosmological constant problem. We're planning to do another one of these before too long, in which I think we'll discuss inflation and more esoteric topics such as the early universe, the multiverse and (I strongly expect) the arrow of time. Hope you enjoy it. Update: Here's a link to the bloggingheads.tv page, where a variety of download formats are available.