I think typically they're done on Reddit these days, but I bet you could do this kind of questions post you refer to on HN and then follow up with a link to a video or stream.
I think that's pretty awesome myself. Closest I've been to that kind of setup is back in.. either middle or high school tech class. We had a separate indoor sound-proofed "room" used for a broadcast channel just for school. Cool stuff.
It's second nature to me, but most people are sort of stunned when they see a broadcast quality studio in my (former) garage.