i break spokes on occasion. sometimes i won't notice until i get home. if the brake pads rub, i'll readjust the brake caliper.
there's no way i would ever attempt to replace a broken spoke on the way to or from work anyway (this is the commuting forum isn't it?

). wouldn't i have to carry a spoke wrench, cassette removal tool, and a chainwhip in addition to one spoke of each length?
i'll live on the edge i guess!