For a few years I played online with a group of really good role players/writers. They were all AOL people using chat rooms. When I joined the group they began to use AIM which was an AOL product along with the message board and web site.
This was really a pretty good way to play at the time, my regular group sort of dissolved and one of the better players invited me to the group. Was pretty hard to get into the clique as some tended to be rather standoffish. But they could rp and write like you would not believe.
One of the characters I had was perhaps my most favorite characters of all time. Most likely because of some of the people I got to play with.
Still, even as fun as it was the politics of dealing with people online was the seed of it's demise. I found that this group of people from around the world had no real ties to one another and they didn't have to be nice and sometimes they weren't. There were problems of immaturity and social dysfunction. You know what they say about genius being very close to the edge. Well some of these people were very good role players. Not your typical good, but very good. I was blessed and cursed to have been able to play with them. Still, I will remember how much I learned from them and hold them as the standard of excellence by which all other role-players will be measured.