Hello! My English is bad (<em>can anybody correct my sentences?</em>), but i want to try to answer. I cannot speak for all the people living in Switzerland, but generally, they leave the shoes before entering houses. We don't want to make dirty the inside of the house. It's a sign of respect to the owners. And it is more polished. In winter, we propose to the guests slippers or thicks socks, because they must be comfortable. In summer, it's different: we often stay with them on the terrace or in the meadow under the trees. In that case, everybody keeps his shoes. But when we live in countryside, it's also nice to be with nacked feet. Be careful not to crush bees, wasps or bugs!

I find it rather impolite if someone asks me to take off my shoes, when he/she let the pet do whatever it want. I mean pets walk on the  street too, don't they?

Here in the Midwest section of the US, it is much like Gabriela describes in Brazil.  Half of my house is carpeted and the other half is tile.  I don't care if my guests leave their shoes on.  If a guest starts to remove their shoes, I tell them "don't worry about it" unless I know the guest is staying for several hours and just wants to get more comfortable.

When I'm at home on the weekends or after work, I'll go barefoot while inside.

When I visit someone else's home, I don't remove my shoes unless requested.  I suppose I view it as polite in that I'm not "making myself at home" unless expressly invited to.

The exception to all this is during winter weather when shoes have ice and snow on them.  It is then customary to remove your shoes just inside the door.

No, it is not much common here in Brazil. Usually when we try to remove our shoes the owners of the house say "don't worry about it". 

We do that in the Netherlands a lot. Not everybody though. Don't tell me you copy that from us during the colonial age?