Habbo Hotel is an online community that combines features of a chatroom with an online game. You create a 2D avatar for yourself and set it loose in the many rooms. You have the Hotel rooms, made by the sitemasters, and you have the user created room. You can play games, get furniture, meet friends.
Be warned, though, cyber-ers abound on certain user created rooms.
Anyone on the forums have an account or interested in making an account that would like to join me to create group mayhem?