At Bay Area Maker Faire 2017, Steve Goldstein and Kevin Jordan made a levitating water fountain controlled by a bike pump for the CrashSpace booth.
The bike pump tricks users to thinking they are pumping air into a fountain to make the water bubble up.
We definitely confused a lot of people at the event.
https://www.instagram.com/p/BUX2izwFqtX/
Full write up at HackADay and CrashSpace