I woke up this morning only to find my bike's rear tube was punctured by a thin steel wire, possibly on my way home yesterday. I searched around for emergency reapir tips, and learned that I could get away with tying a knot around the leaky region in a pinch: I clearly underestimated how stretchy bicycle tubes are and this actually worked. The knot did produce an noticable bulge on the rear tire, but this was enough to get me through my commute. I got the tube repaired at a shop on my way home.