The shoes thing was a bit different for me when I lived in St. Pete, and also living here in Norway. They advised me to bring slippers to Russia (so I wasn't walking around barefoot or only in socks, as it was more polite as well). And I guess it is because of the snow (at least partly). At home in the southern US, we always left our shoes on. But now when I visit home, more and more families seem to be adopting the shoe-less policy. I think its nice.