The polling site will be very helpful to encourage more student involvement and understanding for different topics during class. I like how you can put them into power points or flip charts. Everyone wants to use their cell phone during class and this is a way to do with instant feed back.
The website wallwisher is another great site that can allow for more student involvement from home or the classroom. This site allows us the chance to see what different people are thinking and allow others to view it in a different way. I'll add this to my web page to help for more discussion.