Vastpark apparently will allow you to easily create your own virtual interactive world, which you can then email to a friend or teacher and then post it on a blog or online journal.
This would be a good site for English Language Learners, who could create their world and then describe it and what happens in it.
You can sign-up at the Vastpark website for an invitation to try it — it’s not open to the public yet. Because of that I have not placed a link on my own website yet. In fact, this is the first site I’ve written about that is not up-and-running yet — usually I wait until its open. This one just looks especially intriguing to me.