Is there anything more annoying than being ignored by someone constantly fiddling with their cell phone? Perhaps if sarcastic signs like these were posted in all public places, we'd think twice about taking refuge in our little glowing rectangles instead of experiencing the world around us.
Then again, who are we kidding? People would just take photos of the signs with their phones and upload them to the internet.
UPDATE: The original version of this poster was created by Michael Sumner of Burning Books. See the original and get a free copy here.