I think that there should be a @sit_place command sort of like @sleep_place. And it could just be in bars (at least at first), because that's where most people sit regularly and there aren't many exciting seating messages already built in at most bars.
It would have "sitting at the bar" prefixed to the rest of the message, just like the @sleep_place.
It would look something like this:
@sit_place me is his feet dangling far above the floor.
Joe is sitting at the bar, his feet dangling far above the floor.