When the discussion turns to virtual worlds, it's usually about Second Life, IMVU, the Habbo Hotel, and the like. However, there are some straight up computer games that should really be added to that conversation — specifically, that genre of online games known as massively multiplayer online role-playing game, or MMORPG.
The first MMORPG with a persistent virtual world was a venerable game series called Ultima Online. Originally launched in 1997, by Origin Systems, Inc., it paved the way for all the others. Sony Online Entertainment's Ever-Quest II, a sequel to the enormously popular EverQuest, is another popular game that combines a persistent virtual world with social components. And there are many others.
A growing number of social networks have emerged that focus exclusively on virtual worlds. For example, the membership of Koinup, an image- and video-hosting site and online community for users of virtual worlds, includes members of Second Life, World of Warcraft, Frenzoo, IMVU, Twinity, and Blue Mars, among others. They come together to network and talk about shared issues of life in a virtual world.
These and other MMORPGs support thousands of users, who play the games simultaneously (thus the “massively multiplayer” part of the gaming category). That simultaneous game play led to the game makers adding such social media features as blogs, forums, live chat, and virtual commerce along the lines of what you'd find in Second Life. WoW exemplifies this game-as-social-media model. It's one of the most popular MMORPGs, truly a phenomenon, and it's full of social components.
You maneuver avatars in the consistent world of WOW in the same way you would in a Second Life-type environment. You use your avatars to explore the world, but also to fight monsters and interact with so-called non-player characters that are part of the game. Those avatars also interact with other players' avatars, and even cooperate and work with them to pursue quests — and that requires conversation.