LIttle Po has a bunch of excellent tips on avoiding nastiness in the foot regions. A highlight:
Prepare two pairs of socks and rotate them. If your feet tend to sweat a lot or you are hiking in on an extremely hot and humid day, it’s nice to prepare an extra pair of dry socks to replace those damp ones on your feet. Once you rotate them, you can hang those wet ones on your pack to air dry them. Just make sure none of your teammates gets too close to them!
Speaking of feet, Steve’s WildeBeat has a couple podcasts on Fixing Your Feet that I’ve been meaning to checkout. Part one here; part two here. Happy Feet blog here.