Funny thing it, the experts are saying these masks are useless in the prevention of picking up this flu virus so all these masks effectively are, are just badges stating that the wearer is a hypochondriac. Makes me laugh
That's true in general, but a Japanese colleague pointed out to me that they're common among some Asians because they've been promoted as way of reducing the spread of a disease if YOU have it. If you have the flu, but have to go out anyway, wearing a mask reduces the chance of you sneezing your virus all over the place, and thus spreading it. Something to think about for the original poster.
But of course the virus is mostly spread by surface contact - washing your hands before eating or touching your mouth, is considerably more useful than the masks.