Looking for a material like what forms the sides of leather shoes (think
Topsiders) that resists odor and decay after long life on someone's
foot without socks.  It must be as breathable as the Topsiders are
now.  It would be nice if it were not made of werent't leather, but if
leather is the best at being allergenic, I would like to know why it
behaves so hypo-allergenically.

thanks
Gary

Hope you get a good answer. I coincidently posted a shoe question just
after you, the next third question on I think, and got a great answer
back,(even though I have only just now gone into a  couple of the
links supplied).  I am sure that shortly someone with just the right
info will get back to you soon as is usually the case.

 Bye, going to sleep right now.

You may want to consider a poromeric material:

"The most important property of the poromerics is the microporosity.
The name poromeric comes from the words porous and polymeric.
Microporosity is, in addition to water vapor adsorption and
desorption, one of the most important characteristics of leather.
Before the development of 'Corfam' there were no synthetical materials
which looked like leather and had these properties. The imitation
leather has been made microporous by coagulation or other processes...
Shoes made from these microporous materials are able to breathe
similar to leather. Extensive investigations of wear hygiene have been
reported. Not all of the comfort properties of leather have been
achieved by the use of synthetic materals."

http://www.gofar.co.kr/eng/info/info_12_2.php