Wizard of Oz prototyping

One of the other things which I am presently struggling with is Wizard of Oz prototyping. I am supposed to use this for the project I am doing at my work. I have read research concerning the prototype. Please have a look at the SUEDE video , SUEDE is one of the tools I found while researching for existing wizard of oz tools. However I am concerned about the part of the prototype wherein I am not supposed to be directly interacting and have to give the feeling to the user that he/she is in charge of the system. The technical parts are also somewhat a problem, I am trying to overcome it using some simple scripts using HTML. I was also thinking of using the existing chat system( suggested by my friend Moe) like YM, Gtalk, Skype or etherpad for making the system interactive. Lets see how it works. I am sure I can find a solution.:)