I always carry a light weight flexible hospital mask in my purse and wear it on the plane and have been doing so for quite a while. Way before Sars or any other disease, but on account of the supposedly bad air in planes. I really don't know if it's true, but I always like to err on the side of caution. Since I usually always get sick during a trip, I sure don't want to start out catching something on the flight.

As far as wearing a mask in the cities of Southeast Asia, the pollution is so bad, that policeman wear masks, as well as some locals. No you won't look silly at all.

Have a wonderful time, I know we sure did, no question about that!!!

Cheers, Rose - Los Angeles