Meaning of ところで in Japanese

"By the way, do you know what a Shinto shrine is?" "I've a little bit of knowledge on the subject. It's a religious facility where that which is the object of worship, that called the genius loci, is enshrined."

They are just going to the store over there.

I asked her if she was going out.

Where were you going?

You were so late coming that I was just about to telephone you.

I'm about to tell you the answer.

Oh, by the way, do you know where she lives now?

"By the way, where's your old man?" "Under that over-turned truck."

"Where have you been?" "I've been to the barber's."

"Have you finished it?" "On the contrary, I've just begun."