There was a story on the news a few weeks ago and they did a study to see where people going to a restaurant would pick up the most germs. They checked the tables, chairs, toilets, door handles, etc. What was interesting is where they found the most germs and it was where most people would not think about. The menus!
Everywhere else is usually wiped down, but no one thinks to wipe down the menus or thinks much about handling them.
So the moral of the story was that after sitting down and ordering your meal, you should wash your hands or use a hand sanitizer before picking up that piece of bread.
Another thing that was interesting is that they said it takes approximately 1800 germs to get the flu but only takes 18 germs to get the norovirus. (I could be off slightly on those numbers, but I think that's pretty close.) They also said a flu germ only lasts on the surface for a couple of hours, but a norovirus germ can last a couple of weeks. Nasty stuff this norovirus.
But as was pointed out, it's the second most common bug that we get, next to the common cold. Alot of people are scared to go on a cruise because that's the only place where it's required to be reported to the CDC. Yet it's more common on airplanes, malls, hospitals, schools, etc. and they're not required to report it. When was the last time you saw someone disinfecting the handrail on the escalator at your local mall? Yet you always see them wiping down handrails on a ship.
Bottom line is, as was already stated several times, wash your hands constantly. It's really is the best and easiest prevention.