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SitePoint has published the video of the seminar I did with them, along with some of the Q&A.
We talked about a pretty wide smattering of features, so it was more "A bunch of random interesting things that CodePen can do" rather than the official title "Making the Most of CodePen".
Here's the video:
I'd love to do more of these, perhaps with a more focused look at some of our features. If you'd like to attend one or have any specific questions/ideas, hit me up.