Well, I lived in San Francisco for 3 months (smoking in public places is banned in California) and I thought the law was superb. It was quite incredible to go out on the piss, wake up and not have to wash everything you wore the night before cos it all stank of fags. I did start feeling healthier as well.
I think it would be a bit harder to implement practically in the UK; california has a climate that allows people to go outside if they are in a bar, restaurant, club etc. and have a cigarette. It's not illegal to smoke outside there though - only in public buildings like restaurants and bars. I think that is a good medium. It's a bit ludicrous to try and ban smoking in parks for example.
It would be a defiant act of government to implement it but I would really like it if Labour had the balls to do it. I know a lot of people would start banging on with the "political correctness gone mad" rubbish but that's always going to happen. At the end of the day I dont see why I should breathe in bad air just cos someone is too weak willed to not smoke. I personally see smoking as a mental weakness.
Maybe they should have smoking and non-smoking sections to pubs like they do in restaurants? Having said that I doubt anyone would stick to them in the Uk...