Well as a matter of fact I have created my own culture (Clan) on Star Wars Jedi Academy and I have members who have joined and who we play together. We base it on learning to become a Jedi being one of the fictional cultures in the Star Wars world, I maintain this clan by playing online and have made my own ranks and everything. Iv been making modifications also so that me and my clan can do more exciting things that we can do together. It occupies pretty much most of my spare time and I enjoy it as its not only about playing a game, but its interacting with people who live great distances away.
The members range across Europe and we all have similar interests and still maintain this internet friendship by speaking inside the actual game as well as outside on instant messaging services. (I have flown out and met a few of the members properly and due to the distance we continue to play and get together via the internet)
Its not taken too seriously but things such as playing times and a minimum number of times weekly are enforced but in a more relaxed environment. I think of it as a virtual world which we can spend virtual time together.
It doesn't go to anything where its very political and having very heated arguments against certain people, its a friendly environment and I know of others that can be the contrary.