The "nano quadrotors" title threw me off - I was wondering what kind of magic these things were - artificial intelligence? Clone drones?
Then I watched another vid where the guy built one from a kit and stuck a small video camera on it. Basically for a few hundred dollars you can own your own spy drone!
I doubt I could find the link now, but I watched where one guy had a big one with a 4k HD video camera on it, and the films he made were amazing.
Nice post!