True, and a get back home system which included a bike would possibly need much less in other supplies. For me to walk home would take a minimum of 10 hours. On a bike I could do that in 2-3 hours depending on how many times I was forced to get off and carry the bike -- 2 liters of water for the trip.

I'm not going to start carrying my bike to work just in case, but I can easily imagine me hoofing it to the bike shop near work and either buying or renting a bike for the duration. The other option would be to get half way through the walk and see that TREK sign in the shopping center I drive by on my way to work. A TREK 520 would work quite well depending on tires.