Recently there’s been something of an explosion of mathematical videos. Not only are there “popular math”-type videos (e.g. Vi Hart‘s videos on hexaflexagons and much more), the Simons Foundation has been posting a series of interviews with Deligne, Manin, and others, and more and more conferences are now recorded, such as the introductory workshop “Cluster Algebras and Commutative Algebra” at MSRI in August, and many many lectures of interest at BIRS in Banff (examples 1, 2, 3). These videos are great resources for the community, particular grad students and postdocs. You can “virtually” attend a conference today! Thanks to Irena Peeva for the prompt.