johnwasser's luggage link is pretty good but it is over 20min long. Fast forward 18min to the final product then go back if interested.
The ultrasonic "ears" obviously work.
Pauly's library chairs seem to only be a concept so there is no technical solution there. Having robot chairs follow you round a library does not sound very green. However I found the idea of masses of chairs following the "manager" then forming themselves into a seating plan for an audience quite amusing - I would love to see it.