This is interesting - on the CBS Morning News Show they've been talking about germs and H1N1 and such...today was checking to see how germy your washing machine is! They suggested every 3 to 4 washes, run an empty load with 1 cup of bleach and COLD water (fresh bleach; not the scented kinds; make sure it says 'kills germs' on label) Apparently there can be, well, your regular household germs, but also the coliform germs (from underwear??)
and of course kitchen sponges just soak up and store germs, but you have to wash your pots and pans of course, so take a container of bleach water and drop your sponge(s) in it for a bit, that disinfects them. And they're relatively cheap enough to ditch after a bit anyway.
Keeping germs under control is especially important for those with young children, the elderly, pregnant women, and those with compromised immune systems.