Presenting in front of the class causes anxiety in most people. Don't be afraid to use some tech tools to help with an ice-breaking introduction! Here are a few ideas:
http://blabberize.com/
http://www.xtranormal.com/
You can use these to begin or end a presentation or reiterate an important point. These are very intuitive Web 2.0 tools, but please ask Mrs. Canup if you need further assistance!
For an example of blabberize, check out mine.
