Your mask inspired me to make my own attempt:
Did you do anything special for yours besides square of fabric + elastic? Mine's probably about as effective as holding a finger over my nose, but I'm not really intending mine to be functional. People are even starting to decorate real masks, which is cool! I love this guy's: http://www.telegraph.co.uk/health/healthpicturegalleries/5243655/Decorated-swine-flu-surgical-masks-in-Mexico.html
Good, crafty way of taking one's mind off a terrifying situation!