I tend to alternate between two pairs of footwear, with a third pair thrown in every once in awhile for good measure. For the past month or so, I have been running almost exclusively in either the Vibram Five Fingers and the Nike LunarGlide (yes, they are that electric green -- I like them, but credit goes to Esmé for nudging me along when we were shopping for them together). The third pair of shoes is an older Asics Gel, I think, that doesn't have too much in the way of mileage on them yet.
I wore the Five Fingers again today, trying out a new route around a nearby lake. Didn't feel like getting up early, and had plans for grilling tonight, so I set out for my run at noon. Hindsight, maybe not the best idea. But then again, it might be good practice running in not-always-perfect weather.
In any event, each mile was slower than then the previous one, as the heat and lack of energy conspired against me.
Today's mileage: 4 miles in 40:30.
Total mileage: 40 miles.