Wouldn't it be cool if there was a "Howler" setting for sending messages on cell phones? So if you really wanted to talk to someone or tell them something and they were ignoring your calls you could send them a Howler and no matter what setting the cell phone was on it would just yell it out for everyone to hear. It would have to be regulated somehow so people wouldn't send them as jokes when you are in the movie or something. I think it should be looked into. There are clearly a lot of flaws with the idea, but it could be very beneficial as well.
And YouTube has a music video about Ron getting a Howler. Thanks Harry and the Potters.