I carry my backpack with me everywhere and I always keep an extra tshirt in there. I sweat profusely and so it's embarassing to show up at some place, after having had to run a bit to catch a bus, or if it's really hot out, and be all sweaty and gross. I always excuse myself into the bathroom and change my shirt, and throw on some deodorant. It also comes in handy if you're eating and you spill something on it. Or if I'm going somewhere right after work, I don't have to wear the nasty fibreglass smelling tshirt anywhere. So how about you GF? Are you in the habit of bringing some spare clothes around with you? What kinds of reasons do you bring them for?