Out of all the drones on the show floor at CES 2015, the Micro Drone 2 was the only one I saw demonstrated flying up and down the aisle, (confidently I might add), with no cages or safety devices. Its super small, so it doesn't present any reasonable threat to any attendees but the demonstration was impressive none-the-less.

It went too fast for me to capture on video with manual focus on the Canon DSLR I had in hand, but believe me - it was small, fast, and agile. Plus you can buy it now: Extreme Fliers Micro Drone 2.0