For the Stupid Hackathon 2017, I made a portable wooden rectangle. Every few minutes, it buzzes briefly to deliver a notification. By carrying it in your pocket, you can be notified wherever you are, no matter what you are doing. The medium is the massage.

You can make one yourself! I used an AVR microcontroller and a scavenged cell phone buzzer driven with a MOSFET. The source code is stupid-hackathon-simple.