I agree about being in shape. I am in very good shape. I walk to work (15-18 miles) per week and hike on a regular basis. However the thought of walking 200 miles is not something I would ever want to contemplate. In all likelihood (in my lifetime or the next 400-500 years if we go by the earthquake expert guesstimates) this scenario would never occur but all the replies here have been interesting thus far.

Also keep in mind, the original intent of the post was to get ideas on what type of gear etc people keep on hand in the likelihood that they had to walk any distance on foot.