CNN is all ranting and raving about a University of Michigan study in which some 2,000 students living in the dorms are wearing face masks and using hand sanitizer throughout flu season to empirically discover their effectiveness at reducing the spread of the flu.
Apparently even though there's lots of anecdotes about masks helping prevent illness, there haven't been any real solid data about it. On the one hand, I think it's great that they're getting hard empirical evidence about the spread of flu in preparation for a potential pandemic (as well as studying to sociological/psychological aspects of having people wear masks!), and on the other hand it strikes me as a "no duh!" moment.
And no good story goes un-anecdoted. In Spring 2006, a year ago, I was to start treatments with Remicade, which has immunosuppressant side effects. Because I didn't want to get sick while on it, before I even started the treatments, I started washing my hands or applying antibacterial gel after every class. Prior to doing so, I would typically get a mild cold during the first week of EVERY semester, and often catch a moderate cold during the middle of the semester. I did not get any notable illnesses in Spring 2006, so I repeated it in Fall 2006, also failling to catch ill. This Spring I was sick three days after the first day of meetings of Spring 2007 - I forgot to wash my hands all day.
I went a full year without illnesses, simply by washing my hands three times during my work day, every work day. Give it a try yourself; maybe you'll be pleasantly surprised. BUT do NOT try this with children. They need to build up their immune systems - as adults, ours are already fixed, but kids's immune systems have to learn it's ok to have some amount of germs around. Without continual mild exposures to germs, kids are at a higher risk for developing allergies and asthma, or so the latest research suggests (not that I have a source handy).