I had this on my head for a while.
Bitcoin is a decentralized currency. Why not have a decentralized virtual world to go with it?
There's no central point of shutdown, so if one "world" is down, you can still access another one.
Also, you can't get banned from the entire network.
In the future, they may be more powerful hardware, and more kinds of human interface devices. You should be able to use new technology without hassles.
You can make your own "world" do stuff you want, do permissions, etc.
Each "user" has a unique ID, like Bitcoin addresses. A new ID can be generated at any time, however you may lose your access at certain "worlds".
Worlds:
Each world has an ID. ID has a public key and a private key. The private key is for the controller of the world. The public key is so people can go to that world.
Worlds can be programmable to do stuff, like keep certain users out. Each world should accept a protocol people can agree with. Newer protocols should be made when new types of HID come out.
Currency and trade:
Bitcoin could be what mostly everybody in this virtual world trades in. As I said, this system is easy to build on. An system could be made to identify if an virtual item is counterfeit or genuine. The possibilities are endless.
Users:
Each user would have a user ID. There is a public and private user ID. The private user ID allows the user to control the public user ID. The public user ID is used to identify users.
Interface with worlds:
Any user can connect to any world, however worlds can disallow a user into a world (not responding to the user's request). If a user does not like a world, the user can exit the world at any time.
Processing:
If a user has a dumpster computer (pentium d, dell, etc.) there could be a network of computers that allow these users to connect to a world without needing a new computer. There would be an internal currency that would not allow the user to use the network of processing units excessively.
Suggest your ideas. I have not finished writing this topic up.