I ride a bus to and from the office every day. While I love Ubuntu, getting a constant barrage of "WiFi Available" popups whenever we pass by a coffee shop is annoying as hell. Digging into the network manager every day is a chore. Solution: A simple command line handler with a memorable name:

if [[ -n "$1" ]]; then
nmcli nm wifi $MODE

Typing airplane will turn off your wi-fi stack; typing airplane off will turn it back on. (Actually, typing airplane four score and seven years ago will turn it back on. Any argument is accepted as turning airplane mode off. Even airplane on.)