Some times I miss a notification, and I have to scroll all around to try and figure out who last sent me a message.  It would be great if the rooms, well rooms might be difficult with lots of activity, but people by last contacted.  I could easily look over and see a sorted list of who contacted me last.  It would be a great help.  Not to say that you should be like other chat programs, but I like how gchat orders the People list, shows a snippet of the last msg, and the avatar of the user.  Makes it much easier to navigate.