More GMs should let you do stuff while their NPCs are talking. Even if that would lead to a Gamers-esque situation where the Bandit King can't even get a sentence off before being shot to death...

Players only want talking to be a free action as long as they are the one's doing the talking. I wonder how enforcing it so that it cut both ways would work out. I should try it some time.

It works well in my game. Talking's a free action, as long as you can say it in six seconds. So basically, about 1-3 sentences.

Anything longer than that, and you're talking through your next turn, which can have bad results, such as an enemy passing a Listen check.