Not a Hitchcock sequel

Twice in a week I've been chatting in someone's backyard when my host said something about birds, followed quickly by suspicion about them carrying bird flu. If the H5N1 virus ever breaks loose, I'm pretty sure it's other people and not birds we'll be worrying about. Bird-to-human transmission is only scary to someone spending lots of time in east Asia (and a few other places) close to infected domestic birds like chickens. The real trouble would start with human-to-human transmission, which might happen if avian influenza and human influenza viruses were present in the same body and exchanged genes. A pig is the most likely go-between (more info here).