"Searching For Quest Group" Lobby - Main Quest, Side Quests, Farming
Other games often use tables and people will put up a notice, asking others to help them get through the main quest, side quests, to finish bosses, or just to farm as a team.
The thing is, this often fills world chat with SPAM levels of message flood. And it doesn't create a friendly community.
While the "Team Up" function is good and quick for specific quests, sometimes it's harder to find someone to join. Especially for longer quests.
Perhaps creating a world map specific for people searching for help in a main quest would be helpful. Especially for solo players, who either lack time or patience to try and solo quest through some of the more challenging quests and bosses for their character/build/school. (Also, it's not nearly as fun to quest through everything alone. Especially when it takes so much more time.)
A map where people can chat is fun. And you can add someone as a buddy. (The most memorable players I've encountered have always been found just waiting outside the quest entrance, not using the "Team Up" function. Also, there is no "playing through Main Quest" Team Up function. And less popular farming locations end up with people not even bothering to use the Team Up function. Which is frustrating for rare housing items, for example.)