That depends on whether you're driving or not.
I vaguely remember a post about this on Facebook, or some other waste of time website.

The argument is, that smoking while driving is a distraction, particularly if you're clumsy enough to drop your cig, how would you react? Particularly if you drop it as a reaction to an accident where you need to react quickly.

In this case, you're a danger to other road users and not just harming yourself.

One guy replied, "Oh, I wouldn't do that, I'd just calmly pull over", but the point is, it's not just about one person, it's about how the general public would react in such a situation.

EDIT: For reference, I'm not a smoker, but I'm not against it either, as long as you don't force it on other people, bit like religion really!
(anonymousreality tickled your fancy on, Fri 25 Nov 2011, 12:09, 1 reply)

So you should ban talking, eating,
radios, electric windows, air conditioning, sat nav, passengers and manual gearboxes.

All of these require pretty much the same attention as smoking does.
(username failed moderation, Mon 28 Nov 2011, 16:52, closed)