Dee,
While I have not done this personally, I have seen/heard of examples of teachers using Ning to help students dialogue or interact as the characters.
Following this thread, rather than creating bogus accoutns at sites, you could use Today's Meet (http://todaysmeet.com/). This site creates a closed Twitter-like chat session in which students post in 140 characters or less each time they speak. You can copy and paste atranscript into WOrd, Googel DOcs, etc if you wish to preserve the conversation.
In practice, you could assign each student a character or a viewpoint or an opinion position, etc. Then, have them login to a session, use their position as their moniker, and have at it.
This would work for any number of lit pieces, or social studies, etc
Just perused Andrew's site...WOW! Most of the technology discussion in our PD centered around much of the tools listed on his site. Will definitely look into making a novel movie trailer and using Toon Doo for chapter reivew/character sketch kinds of activities.