FAKEbook

Fakebook is a website where users can posed as other users, such as celebrities or random strangers. According to the site, it is meant to be used for an educational purpose:

 "Use "Fakebook" to chart the plot of a book, the development of a character, a series of historical events, the debates and relationships between people, and so on!" 

I personally would just use it to be silly and when I'm bored, however, I can see the benefits of using it as a study tool and gather an understanding of the series of events that occurs in books/textbooks.  

In addition, users can save their work and return at a later date. I'm personally am having a lot of fun with it, so I think I'm going to continue to when I finish this post hehe.