I commute into the city of seattle (bout 17 miles each way) and i would say aside from the normal lights/clothes etc.. .my suggestion would be either full fenders in the winter, or at a removable rear fender, and some ultra gatorskin tires + that puncture stripping to help prevent punch throughs... really, for me it all about avoiding flats since i commute at 4:30am and changing a tire in the dark, when it's 30 degrees. sucksmuch@ss... good tires are the #1 if you have to travel on city/industrial roads that are awash with bolts, glass, steel belt threads, + seattle potholes.