Just wanted to add a couple thoughts that may be of some help to someone out there with Plantar Fasciitis.
I currently work at a furniture store and I am on my feet a lot, with a staircase I use often. I do have an opportunity to sit frequently. The exercise I get seems to be helping the PF, maybe the stairs are good exercise. My problems were much worse when I used to drive for hours between accounts.
At work I wear New Balance 700 casual leather walkers, and SAS "Time Out" walkers, and occasionally on short days I wear NB 735 dress shoes. All are leather, and present a "dressed" professional appearance. I've found it's very important for me to wear these shoes to minimize the discomfort of the PF at work.
PF is NOT something you only get from a week of walking at WDW, you have it all the time, it just gets worse when you are walking at the World for 5 or 6 days in a row. From my experience, wearing these "better" shoes at work on a daily basis, gives me less discomfort when I am walking so much for that one week at WDW.
The SAS shoes are more expensive than NB, but I find they provide equal comfort.
I have not had any success with heel pads or heel cups. In some cases they seemed to worsen the problem. I have tried a lot of different ones.
I have also found that the minimal cushion effect of socks is very important if you have PF. Please just take my word for it!
The limping I experienced at WDW from painful blisters on the toe bottoms may have aggravated the PF by altering my normal walk. Not sure about that. The Shea butter seemed to eliminate the blister problem and now I use it every day. No blisters = no PF?
I just hope what I have had to say, and what everyone else has contributed to this thread (especially CanadaPT), will help someone out there enjoy a whole week of walking at WDW without the AGONY OF DE FEET!