Here's some that I've been handing out. It's designed to get people to look into it (by telling them not to). You print them out on one piece of paper (duplex printing) and cut them into 8 cards per page. I've even been laminating them for placement outside.

Side 1: https://postimg.org/image/w9gecqp1v/ Side 2: https://postimg.org/image/4xgjxnuxf/