Since I kinda bashed guilds in general in the last post, and Rich made a comment about it, I've decided to talk briefly about guild/Player Association systems.
Guilds in most MMORPGs serve only for organization and bragging purposes. Most games just have them delegated to purely social aspects. Most Guilds don't own or control anything, and most don't innately have the ability to tax or require dues from their members. These aspects have to be controlled by the actual players, and enforcement is difficult at best.
In World of Wacraft, guild leaders have to delegate who sets up the guild bank character, who is in control of what and largely create most of the ranking and title system in the game. The guild doesn't have a place to call home, nor any place to display their trophies. Social Networking and mutual support are about all that's available here.
In Star Wars Galaxies, the Player Associations have a set location, their Guild Hall, which they can decorate and use for storage, but players have to act as a money storage, and there is still no way to tax or require dues from players, short of charging an entrance fee to the Guild Hall. Most Player Associations use faction bases as their unofficial HQ, as they can be defended and destroyed and it adds a bit of flair to the game.
City of Heroes gives Supergroups the ability to build and design a base (and pay for it). I don't know off hand if they have a tax system, but they do have a banking and item storage system in the game for Supergroup bases. These bases can be attacked and defended, and loot rewards can even be stolen. It adds a fun PVP availability.
I, for one, believe that guilds should have some playability beyond just being a social group. I don't join a guild to raid, I join one to have fun, and not having a physical place in the virtual world to call a guild HQ really bothers me as a player. Leave a comment and tell me what you want out of a guild.