Several of my talks are now on YouTube, and I've archived them on this playlist. Some highlights include:

On the Expressive Power of Programming Languages, a tribute to my favorite paper (at Papers We Love, 2019)
Teaching Computational Thinking, about what's problematic about that term (hosted by EPFL, 2018)
Curriculum Design as an Engineering Problem, a summary of the design of Bootstrap (hosted by Jane Street, 2018)
About the first seven minutes of the former (EPFL) talk are very similar to the first ten minutes of the latter (Jane Street) talk, but after that they largely diverge other than some brief overlap near the end.
The Role of Computer Science in Computer Science Education, about what computer scientists have to offer to education (a plenary talk at FCRC 2019)

I sometimes also upload videos of tools we've created (or that I like).

Some of my older talks are also on-line:

I also did an interview with Erik Meijer (2009) for MSDN's Channel 9. We talked about types for JavaScript, event-driven reactivity, Flapjax, and programming environments on the Web. Totally uncut. So raw it bleeds. Sort of.