"Find it a bit offputting though when the postman waves to let me know he has a parcel etc when I am sitting on the floor playing with my DD".
Our postman came and knocked on our window when I was EXPRESSING!!!!
He was a seriously nice guy though, dad of four, and he'd done it as he knew we had a new baby and didn't want the doorbell to wake her. So I couldn't be cross.
People look in our windows. I just smile/wave if we make eye contact, I recognise most of them anyway as it's quite a friendly area. I do pull the curtains if the kids are making me dance like a looney though.
I do look in other people's windows, not intentionally, but my eyes get drawn that way. Don't think it's a big deal, if people are worried they should have blinds.
In fact, the street we walk down to DS's school the living rooms are right on the pavement. They ALL have blinds - very sensible.
They also nearly all put little displays out on the street side of the blinds, or the blinds - trophies, collections, Halloween/Easter/Christmas displays. We are surely supposed to look at those, only someone outside can see them.