Technologies from stupid.com:

“With some people, it’s impossible to get off the phone.
Meet the Get off the phone excuse machine:
with just a press of a button, you’ll have a solid excuse that’ll get you off the phone, no questions asked.”.

Two examples:

Static: Press this button and say, “I can’t hear you. You’re breaking up!” Then just hang up the phone.

Car crashing: Just say, “Oh, my god!” and hang up.

“Sometimes it seems like mothers speak a different language.
Well, thanks to modern science and vivid imaginations, you can now instantly understand your Mom.

All you need is this Understand Your Mother Instantly Breath Spray!”.