Haha.. I keep a full set of undergarments, an extra t-shirt and some shorts in a drawer at work. same goes the kotex. Another good thing to do is to stick with the same backpack day in day out. I always forget things when i change bags.

but i'm lucky, my commute is rather short (for now) and I live in a city, so i figure if i had a flat, a taxi is 2 fingers away.