My town is a small one but not a very pet friendly place, you don't see people with their dogs out in stores or restaurants here.
I've seen many, many dogs left in cars alone though and I would rather leave my babies home than leave them alone in a car.
If we had places that welcomed our pets then I would definately take mine.
They go with me on short trips like to the bank drive thru or if I'm just going to go pick up dinner at the drive thru.