I'm the same with my kids. If we're out somewhere and someone lights up, I nicely ask them to put it out or move right away.

Apart from the whole passive smoking thing, Zeke still has a stridor (sp?) from his first heart surgery (the surgeon nicked a vocal cord with the scalpel and he has a paralysed vocal cord).

I was out at the park yesterday, and there was a mother there with her baby son smoking away while she held him. It's just not worth the risk IMO.