What would be ideal—though I don't know if it's practical—would be a way for the game to keep track of when each person is currently located, so as to make sure that only people who are reasonably in sync can RP together. This would have to have a time and a current-time-resolution—because in fast-paced magical battles, you need to be able to keep track of minutes or even seconds, and someone who's in the middle of a battle at Time X by the docks shouldn't be able to break away and run to a battle at Time X-2 minutes at the palace. On the other hand, if you're sleeping or traveling for hours, someone else who's in the same general vicinity should be able to meet up with you and start interacting, even if they didn't happen to be at the same second as you beforehand.
Not sure exactly how to implement this; like I said, this is sort of an "I wish it could be this way" sort of thing.
