While doing some research I came across chatbots, there seem to be quite a varied range of bots out there for use.
The technology seems to be progressing well with people integrating the chatbot with other forms of simulation for example second life. http://www.chatbots.org/chatbot/mike. A downside with the second life bot is that it is not readily accessible to students.
For example you have install second life >>>> create avatar >>>> then find the avatar before you can begin. One use of second life which I find particularly interesting is the ability to hold pretend events and simulations. For example the Second Life English island has a holodeck area, which loads up different scenarios for the user like ordering food from a takeawsay etc.
Chatbots were originally started using text editors from which the bot would reply in text format. Currently the bots can take on many forms like allowing the user to type in a sentance and reply by voice. The use of this in ESL is very useful as it allows the student to practice on someone at anytime. Notice I said someone in the previous sentence, it honestly feels like there is someone on the otherside.
What is currently missing is a bot on which a student can practice speech.